Citizens for a Better FlatheadJanuary 22, 2008
Comments Regarding the Glacier Town Center —Mall Proposal for the
Kalispell City Council
Three points we would askyou to consider as you move forward in our
consideration of this #2 fication.,
1. Before taking action on any one of these three decisions on annexation, zoning, and
subdivision for this development, take time to review the proposed findings and
conditions for each one. only take action when you are fully ready to take action
on all three decisions.
2. Make certain that all of your questions and those the public have raised are answered.
Make certain that you have reviewed and considered the evidence the applicant,
planning staff, and public have presented and that you evaluate the merit of each and
reflect these in your findings. Citizens for a Better Flathead is submitting
significant new information tonight as is permitted under state law for issues of
significant concern to the public including a certified traffic engineer's review of
the Krager Traffic Impact Study for the Glacier Town Center, we ask that you
carefully review and consider this review.
3. Take the time you need to make a sound decision. Make sure you have the
information you need. The magnitude of this land use decision and particularly
the negative traffic impacts it can have warrants you taking the time to get this
decision right.
You Have Before You Three Decisions and Three Different Sets of Rules
That Govern Them
Common General Provisions Under These Three Sets of Rules:
1. You must make these decisions in this order first annexation, then PUD/zoning, and
then finally subdivision.
2. You must adopt separate findings l for each decision and thus you need to be sure you
have sufficient information2 to base these findings in compliance with applicable
annexation, zoning and subdivision laws.
' " �47 Lastly, basic principles of administrative and zoning law require these findings in order to
develop an adequate administrative record. As we have stated previously, it is a "general principle of
administrative law ... [that] the record developed by an agency ... serves to flesh out the pertinent facts upon
which a decision is based in order to facilitate judicial review." North 93 Neighbors, 130 (quotation omitted)."
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Time Restraints:
■ There are no set time limits within which a request for annexation by petition by wolford
Development must be made by the city council. You can and must take the time you need to
ensure that the city can provide (or has so conditioned this annexation agreement to ensure
the developer will provide) the level of services annexation laws require of the city.
Ike uest for or Consideration of New Information:
■ You have no limits on requesting new or additional information and the right and the
duty to request sufficient information on which to base your decision for annexation.
Issues of Law:
■ A decision on annexation is to be based on its merits (Is it good for the city or not good
for the city?) It should be based on findings as is consistent with Montana case law as cited in
footnote 1 and 2.
■You can impose conditions to your decision for annexation as in " 7-2-4203.
Imposition of conditions for approval of addition. (1) The council has power by ordinance
to compel the owners of these additions to lay out streets, avenues, and alleys, so as to have
"The record made before a board of adjustment is essential to an enlightened determination of its
action by a governing body or by a court on review." E.C. Yorkley, Zoning Law and Practice vol. 3, § 18-9(f),
18- 62 (Douglas Scott MacGregor ed., 4th ed. Lexis 2007). The absence of a developed record in this case places
the Court "in the untenable position of having to substitute its own judgment for the Board's judgment." North
93 Neighbors, ¶ 30." DA 06-01735 IN THE SUPREME COURT OF THE STATE OF MONTANA 2008 MT 1,
FLATHEAD CITIZENS FOR QUALITY GROWTH, INC.,Plai.ntiff and Appellant, v. FLATHEAD COUNTY
BOARD OF ADJUSTMENT.
2 To determine whether an abuse of discretion has occurred, we examine "whether the information
upon which the Board based its decision is so lacking in fact and foundation that it is clearly unreasonable and
constitutes an abuse of discretion." North 93 Neighbors, Inc. v. Bd of Co. Commissioners offlathead County,
2006 MT 1325 ¶ 445 332 Mont. 327, ¶ 44, 137 P.3d 5573 ¶ 44 (quotation omitted).
3 7- 2-4601. Annexation by petition. (1) The boundaries of any incorporated city or town may be altered and
new areas annexed as provided in this part.
(3) (a) The governing body of a municipality need not submit the question of annexation to the qualified
electors as provided in subsection (2) if it has received a written petition containing a description of the area
requested to be annexed and signed by:
(i) more than 50% of the resident electors owning real property in the area to be annexed; or
(ii) the owner or owners of 50% of the real property in the area to be annexed.
(b) The governing body may approve or disapprove a petition submitted under the provisions of subsection
(3 )(a) upon its merits. when the governing body approves the petition, it shall pass a resolution providing for the
annexation.
4 7-2-4601. Annexation by petition. (3)(b) The governing body may approve or disapprove a petition submitted
under the provisions of subsection (3)(a) upon its merits. when the governing body approves the petition, it
shall pass a resolution providing for the annexation.
2
the same correspond in width and direction and be continuations of the streets, avenues, and
alleys in the city or town or in the addition thereto contiguous to or near the proposed
addition. (2) The owner of any addition has no rights or privileges unless the terms and
conditions of the ordinance are complied with and the plat thereof has been submitted to and
approved by the mayor and council and such approval endorsed thereon."
00- Because this property is currently covered by county zoning and the county growth policy,
you do not have the authority to act on a zoning or subdivision request until this property is
annexed. See MCA 76-2-310. Extension of municipal zoning and subdivision regulations
beyond municipal boundaries.
■ Kalispell zoning "27.03.010 Application of District Regulations... (4) The city council
shall determine the appropriate zoning for any and all areas to be annexed to the city but
shall request a recommendation from the Kalispell City Planning Board and Zoning
Commission. The adopted Kalispell Growth Policy shall be the primary consideration
in the selection of an appropriate zoning classification. When such zoning of annexed
territory is to be effective at the time of such annexation, the planning board shall have held
a public hearing in order that the city council may determine the proper zoning by an
amendment to be effective upon the effective date of such annexation."
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Time Restraints:
■ The city can not take any zoning or subdivision action until the land has been fully
annexed into the city; thus deadlines for approval can not begin until the land is annexed.
The city can not impose timelines for approval on land that is covered by county zoning and
that is not within its municipal boundaries without an inter -local agreement in place. There
is no inter -local agreement in place.
Request for or Consideration of New Information:
Op- You have no limits on requesting new or additional information and the right and the
duty to request sufficient information on which to base your decision for annexation. Because
5 76-2-310. Extension of municipal zoning and subdivision regulations beyond municipal boundaries (1)
Except as provided in 76-2-31.2 and except in locations where a county has adopted zoning or subdivision
regulations, a city or town council or other legislative body that has adopted a growth policy pursuant to chapter
1 for the area to be affected by the regulations may extend the application of its zoning or subdivision
regulations beyond its limits in any direction subject to the following limits:
(a) up to 3 miles beyond the limits of a city of the first class as defined in 7-1-4111;
(b) up to 2 miles beyond the limits of a city of the second class; and
(c) up to 1 mile beyond the limits of a city or town of the third class.
(2) when two or more noncontiguous cities have boundaries so near to one another as to create an area of
potential conflict in the event that all cities concerned should exercise the full powers conferred by 76-2-302, 76-
2-311, and this section, then the extension of zoning or subdivision regulations, or both, by these cities must
terminate at a boundary line agreed upon by the cities.
6 75-2-310. Extension of municipal zoning and subdivision regulations beyond municipal boundaries.
annexing property requires that you zone it at the same time, you should get all the
information you need and review the existing information you have received prior to making
an annexation and zoninglPUD decision.
Issues of Law:
■ Zoning must be consistent with the Growth poliey.7 In addition to the growth policy
text that includes the Highway 93 North Growth Policy Amendment the plan " g staff has
cited that you must be consistent with, there are goals and polices in the Transportation
Chapter that identify U.S. 93 as a major arterial and provide you guidance on limiting access
to these roads so as to reserve the capacity of these arterials to carry through traffic and to
minimize congestion and enhance safety. The review of the traffic study CBF is submitting
to you today establishes a record that the current traffic plan for the Glacier Town Center fails
to meet these goals and policies.
■ Zoning must be based on findings that demonstrate under state law and Kalispell
,honing Regulation 27.30.020 the following: "Upon initiation of an amendment by the city
council or the zoning commission, or upon petition from a property owner, the zoning
commission shall cause to be made such an investigation of facts bearing on such
initiation or petition as will provide necessary information to assure that the action of
each such petition is consistent with the intent and purpose of this title."
These laws also require that when considering an application for amendment to the Official
zoning Map, the zoning commission and city council shall be guided by and give
consideration to twelve criteria. The following are particularly relevant:
(1). Whether the new zoning was designed in accordance with the growth polio .
(2). Whether the new zoning was designed to lessen congestion in the streets 9 1
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7 76-1-605. Use of adopted growth policy. (1) Subject to subsection (2), after adoption of a growth policy, the
governing body within the area covered by the growth policy pursuant to 76-1-601 must be guided by and give
consideration to the general policy and pattern of development set out in the growth policy in the:... (c)
adoption of zoning ordinances or resolutions.
76-2-304. Purposes of zoning. (1) zoning regulations must be:
(a) except as provided in subsection (3), made in accordance with a growth policy; and
(b) designed to: (i) lessen congestion in the streets; (ii) secure safety from fire, panic, and other dangers;
(iii) promote health and the general welfare; (iv) provide adequate light and air; (v) prevent the
overcrowding of land; (vi) avoid undue concentration of population; and (vii) facilitate the adequate
provision of transportation, water, sewerage, schools, parks, and other public requirements....
9 "¶55 In light of the plain language of FCZR § 2.06, we agree with Citizens that the District Court erred, and
that the Board abused its discretion in issuing the CUP. The Board's own findings show that substandard roads
will see an increase in traffic due to Tutvedt's operation, yet its decision is devoid of any factual findings or
foundation to show how the conditions it attached to the CUP will address those impacts. The Regulations
specifically require the Board to ensure that there are available and adequate streets and access to support
Tutvedt's operation." Page 30, DA 06-01735 IN THE SUPREME COURT OF THE STATE OF MONTANA
2008 MT 1, FLATHEAD CITIZENS FOR QUALITY GROWTH, INC., v. FLATHEAD COUNTY BOARD
OF ADJUSTMENT.
" In this case, the Board abused its discretion by failing to provide such a factual foundation for its decision,
other than a belief that compliance with unspecified DEQ regulations will automatically be sufficient to
discharge its duties under the FCZR. Page 32, DA 06-0173, IN THE SUPREME COURT OF THE STATE OF
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(4). whether the new zoning will secure safety from fire, panic, and other dangers.
(9). Whether the new zoning will facilitate the adequate provision of transportation,
water, sewerage, schools, parks, and other public requirements.
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Time Restraints:
■ The city can not take any zoning or subdivision action until the land has been fully
annexed into the city, thusdeadlines for approval can not begin until the land is annexed.
The city can not impose timelines for approval on land that is covered by county zoning and
that is not within its municipal boundaries" without an inter -local agreement in place. There
is no inter -local agreement in place.
■ Under Kalispell Subdivision Regulations2.04 (C) (E) "within 60 working days the
governing body shall approve, conditionally approve or deny the proposed subdivision
according to Section 2.05.1) of these regulations, unless the subdivider and the subdivision
administrator agree to an extension or suspension of the review period."
Request for or Consideration of New Information:
00- While decisions made under annexation or zoning can continue to request and consider
new information for as often and as long as needed, specific rules apply when new
information is introduced after a public hearing has been held on the subdivision
application. According to the city's subdivision regulations and state law when, as Citizens
for a Better Flathead is doing tonight, new information is introduced after the public hearing
on the subdivision the governing body must. -
"Kalispell Subdivision Regulations "2.06 D 4. If new information or analysis of
information, that has never been submitted as evidence or considered by the planning board,
has been submitted to the City Council, the Council shall proceed as set forth in subsection
(a) below.
a. If the City Council determines that public comments or documents presented at the public
hearing constitute new information or an analysis of information regarding the subdivision
application that the public has not had a reasonable opportunity to examine and on which
the public has not had a reasonable opportunity to comment, the City Council shall determine
whether the public comments or documents are relevant and credible with regard to the
governing body's decision, pursuant to subsections (c) and (d) below.
b. If the City Council determines the information or analysis of information is either not
relevant or not credible, then they shall approve, conditionally approve, or deny the proposed
MONTANA 2008 MT 1, FLATHEAD CITIZENS FOR QUALITY GROWTH, INC., v. FLATHEAD
COUNTY BOARD OF ADJUSTMENT.
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76-2-310. Extension of municipal zoning and subdivision regulations beyond municipal boundaries.
5
subdivision without basing its decision on the new information or analysis of information; or
c. If the City Council determines the new information or analysis of information is relevant
and credible, then the City Council shall direct the planning board to schedule a subsequent
public hearing.
d. The planning board shall consider only the new information or analysis of information that
may have an impact on the findings and conclusions that the City Council will rely upon in
making its decision on the proposed subdivision. 6. New information or analysis of
information is considered to be relevant if it may have an impact on the findings and
conclusions that the City Council will rely upon in making its decision on the proposed
subdivision.
7. New information or analysis of information is considered to be credible if it is based
on one or more of the following:
a. Physical facts or evidence;
b. Corroborated personal observations;
c. Evidence provided by a person with professional competency in the subject matter; or
d. Scientific data.
8. If a subsequent public hearing is held pursuant to subsection D.5.c above, it must be held
within 45 days of the City Council's determination request of a subsequent hearing. Only the
new information or analysis of information shall be considered at the subsequent public
hearing. a. Notice of the time, date and location of the subsequent hearing shall be given by
publication in a newspaper of general circulation in the county not less than 15 days prior to
the date of the subsequent hearing. b. At least 15 days prior to the date of the subsequent
hearing, notice of the subsequent."
Issues of Law:
D. ACTION BY THE CITY COUNCIL:
Upon receipt of the Planning Board recommendation, the City Council. shall:
1. Review the application, Planning Board recommendation, staff report, public comments,
and other related information, and thereupon, shall adopt the written findings of fact as
presented by the Planning Board or make and adopt new written findings of fact. 12
Such findings shall be based on the following:
a. Effects on agriculture and agricultural water user facilities;
b. Effects on local services;
c. Effects on the natural environment;
d. Effects on wildlife and wildlife habitat;
e. Effects on public health and safety;
f. Conformance ,with the following:
(1) These regulations;
(2) The City of Kalispell Zoning Ordinance;
(3) The Kalispell City -County Master Plan;
(4) The Montana Subdivision and Platting .Act.
12 Case law cited earlier regarding adequate findings of fact apply here as well.
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2. Based on the above findings, the Council shall then approve, conditionally approve, or
deny the preliminary plat within 50 working days of the Planning Department's notice of
sufficiency to the subdivider or the subdivider's agent, unless the subdivider consents
to an extension of the review period. A subdivision shall not be denied based solely on its
impacts on educational services."
Conclusions:
• You can not make a zoning or subdivision decision until the property is
annexed and under your jurisdiction. There is no time limit for a request for
annexation by petition by the property owner.
• Take the time you need to obtain information and to make a sound decision for
the residents of this valley regarding the Glacier Town Center and the transportation
issues that are central to this proposal.
• Adopt findings of fact based on sound evidence.
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Alternate Street Des'l n P.A.
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1 � 1516 Plainfield Avenue, Orange Park, Florida 32073-3925
904-269-1851, Fax 904-278-4996, Email: mjwallwork@comcast.net
January 22, 2008
Mayre Flowers
Executive Director
Citizens for a Better Flathead
Po Box 771
Kalispell, MT 59903
RE: Review of traffic issues related to Glacier Town Center
Dear Mayre:
I have read the Glacier Town Center Traffic Impact Study prepared by Krager and Associates Inc.
for Woldford Development that you provided, and undertaken a series of capacity analyses,
reviewed the trip generation and trip distribution and capacity analysis.
My 36 years of background as a practicing traffic engineer includes the following including 32
years designing and reviewing intersections and roundabouts:
• Section Leader, State Traffic Signal Design Section, then State Traffic Signal Engineer
(VicRoads, State of Victoria, Australia, equivalent to a Department of Transportation in the
US)
• District Traffic Engineer, (VicRoads, Australia)
• Traffic operations engineer (South Carolina, and Florida Departments of Transportation)
• Permits Engineer (Florida Department of Transportation)
• Consulting Traffic Engineer, Alternate Street Design, P.A.
In reviewing this report my comments are as follows:
Firstly, a general comment. When I was a Permits Engineer traffic impact studies for developments
of this size required a large study area, especially for developments that generate 75,000 trips per
day. As a result, more road and intersection improvements would be required of the developer.
Road Network
The area east and west of US-93 north of US-2 has an excellent road network that, if maintained
and added to with an infill grid network, will reduce vehicle trip lengths, reduce the width of roads,
minimize the size of intersections, and significantly reduce traffic congestion and reduce the cost of
building and maintaining the road network.
However, the proposed Bypass road will destroy a considerable part of this grid and concentrate
traffic to roads with overpasses. In addition, the Bypass and its many interchanges will remove a
considerable area of taxable land from the tax rolls and create multiple conflict points along the
Bypass.
One significant impact of the Bypass will be to sever the direct access to Glacier Town Center
provided by west Reserve Drive, a very good east/west road. An upgrade of West Springcreek
Road and even Stillwater Road could provide alternate routes for large vehicle volumes at a much
lower cost and with less impact on the community.
My comments are in addition to the issues raised by the Montana Department of Transportation's
(MDT) review of the project that noted inconsistencies with the traffic volumes and other concerns.
Some of the more important issues MDT raised are:
1. The TIS did not mention the impacts on the system if proposed road projects are not
built current with the Glacier Town Center phasing, such as the Bypass and proposed
improvements to whitefish Stage and West Reserve Drive.
2. Control of the significant vehicle conflicts at west Reserve Road and Access C that
typically would require signalization or a roundabout requires resolution.
3. The need for a new traffic counts to reflect recent developments and growth.
Overview of the Bypass Design
Concept
During my 36 plus years as a practicing traffic engineer in several countries, that included bypass
road projects, I found that bypasses typically falls into two categories:
I . Regional bypasses located several miles from the town or city they are bypassing. These
bypasses are based on the elimination of problems associated with access by limiting the
number of interchanges and buying up access rights around the interchanges. These remote
bypasses provide the safest, most efficient road for managing through vehicles and large
trucks. It also creates the maximum benefit to downtown retail by preventing the shift of
retail from the downtown to the bypass road to the bypass road and/or interchanges.
2. Internal bypass roads built along similar lines to the Kalispell Bypass that cut through or
close to existing developments can depress adjacent property values, downgrade the street
networks, and reduce overall access and movement within a community. They also force
more traffic to fewer locations causing more intersections to fail. Congestion and crashes on
these roads increase because of the concentration of vehicles.
Funding and building an interchange at Church Drive and U.S. 93, to service new development in
that area reinforces the view that this Bypass is more orientated to servicing local development than
functioning as a true regional Bypass. A longer -term problem with this approach is that local traffic
will absorb the Bypass capacity at a time when it truly is needed as a bypass. The addition of
signalized intersections along the Bypass at West Reserve Drive, Access B and at Rose Crossing to
service Glacier Town Center development destroys a large part of the capacity and effectiveness of
the Bypass and therefore permanently changes the regional effectiveness of the Bypass around
Kalispell and north to whitefish.
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Termination Design and Impact on Bypass Capcity
The Bypass terminates at a very large signalized intersection. Typically, a bypass starts and
terminates at a flyover interchange with no at grade intersection. Drivers start and finish on rural
arterial roads. Signalized intersections reduce the capacity of a road. Signals at a bypass entry/exit
stop the major road to provide green time to side streets and green time for turn phases. The more
turn phases the less time for the major road. In this case, Page C-68 of the Krager and Associates
Traffic Study, shows that the Bypass through traffic only receives 42 percent of the green time, 50
out of 120 seconds, even less if, with the use of appropriate all -red time. The westbound through
traffic only receives 30 percent of the green time cutting its capacity to only 30 percent of its mid -
block capacity. Two second all red phases, the minimum needed for reasonable safety will further
reduce the green time and hence the road capacity.
The signal analysis on Page C-68 for the BypasslUS-93/West Reserve Drive does not include
pedestrian phases. As walking becomes a more normal part of life in Kalispell pedestrian phases
should be part of all signal designs because, in some cases, they can have an impact on the cycle
time and signal operation. The lost time used in this analysis is 4 seconds. Large intersections,
similar to this intersection, a two second all -red period combined with the 3.5 second yellow for a
total of 5.5 seconds lost time is more appropriate.
Another problem with signals at this intersection is located on Page C-69 of the Krager and
Associates Traffic Study prepared in July 2007.
• The 95th percentile queues for the northbound and westbound through traffic "Volume
exceeds capacity, queue is theoretically infinite." As intersections approach saturation,
vehicles approaching an intersection exceed the capacity of the intersection to discharge
them, causing large and rapid increases in vehicle queues. Capacity analysis programs
estimate either these long queues or note, as in the case of the TIS that the queues may be
infinite. In simple terms, although the average delay to vehicles is within acceptable limits,
excessively long vehicle queues cause drivers to seek alternate routes, often through
neighborhoods, and increase the congestion at other intersections.
• Eastbound left turn, "95'th percentile volume exceeds capacity, queues may be longer". The
listed queue length is 364 feet.
• Four of the 12 vehicle movements operate at level -of -service E, including two through
movements and two left turn movements.
• Typically, the combination of two infinite 95 percentile through queues and four of 12
movements operating at LOS E is cause for rejection
A review of the other intersection analyses showed that in the 2009 and the 2030 analyses there are
many instances of through and left turn movements operating at LOS E with 95,' percentile queue
lengths exceeding the stated values or being infinite in length.
As a past Permits Engineer, both figures would be of considerable concern and reasons for rejection
of the project without improvements to the distribution and intersection capacities.
Traffic on the Bypass will be further constrained by the signalized intersections at Access B and
Rose Crossing.
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Bypass Safety
The provision of multiple, closely spaced interchanges will increase the number of conflict points
and have a negative impact on the safety of the Bypass.
According to the National Highway Safety and Traffic Authority, NHSTA, signalized intersections
comprise 2 percent of the road network but are the location of 20 percent of road crashes. A review
of Chapter 5, Problem Identification, City of Kalispell Transportation Plan, reinforces the concept
that signalized intersections are dangerous. This report indentified high crash locations in Kalispell.
All of the top crash locations are signalized intersections some of which have very high crash rates.
Listed at number eleven is the intersection of US-93 and Reserve Drive with 26 crashes in three
years.
Traffic projections in the TIS increase the traffic volume at the US-93 and Reserve Drive
intersection from 2,530 to 5,404 vehicles per hour, a 213 percent increase. If the crash rate remains
the same at 0.89 then the number of crashes should increase to 55 crashes from 26 crashes in three
years. With the huge increase in traffic volumes, the likelihood of a fatality increases significantly.
An alternate design for the Bypass would extend it to the north across West Reserve Drive to merge
with US-93 just south of, or north of. Church Street interchange. Then the full capacity of US-93
would extend through to US-93 north or Rose Crossing. This design also eliminates a high crash
location at the signalized intersections along US-93 from West Reserve Drive to Rose Crossing
intersection.
Prior to its failure in 2030, because of congestion at the West Reserve/US-93 intersection, total
northbound Bypass traffic of 1,517 vehicles per hour, is less than the capacity of a single
unobstructed vehicle lane flow of 1,900 vehicles per hour per lane or 3,800 vehicles per hour in
two, unobstructed lanes.
Put another way, the Bypass will fail at onl 40 rcent of its unobstructed capacity because it is
terminating at a signalized intersection rather than merying with US-93 north of Rose Cross in . The
same is true for the southern terminus of the Bypass.
Alternatives to a true regional Bypass design that merges with US-93 at, or north of, the Church
street interchange are:
1. Upgrading the north/south roads and east/west roads west of US-93 by and improve the
intersection capacities by using roundabouts.
2. Combining a flyover US-93 at West Reserve Drive with an at grade roundabout to
control the turning movements and West Reserve Drive traffic.
If the Bypass must proceed along its current alignment, there is wide acceptance and understanding
that it will fail at less than 40 percent of its capacity, and item two above is rejected, then
consideration should be given to replacing the signalized intersection at the Bypass, US--93 and
West Reserve Drive intersection with a modern roundabout.
A modern roundabout using the lane arrangement to the left is expected to provide a superior level -
of -service to the signalized intersection, LOS C average delay of 20.6 with a maximum 95ffi
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percentile queue of 415 feet, versus the signalized intersection LOS D average delay of 44.3 with
signals that have four failed movements, and infinite vehicle queues. Note that this roundabout
includes 14 entry lanes and the suggested signalized intersection includes 17 lanes.
Because the predicted traffic will increase gradually over a 20-year period from 2,540 to 5,404
opening this roundabout as a three -lane roundabout may be an overdesign. An alternate concept is
to construct the roundabout as shown but block some of its lanes temporarily, as I have designed for
a number of roundabouts across the US. The benefit of this gradual approach is that it permits
drivers to become accustomed to a two-lane roundabout and accustom themselves to a three -lane
roundabout with the gradual removal of the lane blockages. The busiest two-lane roundabout in
Clearwater, Florida, had a maximum daily inflow of 58,000 vehicles per day. A newly opened
three -lane roundabout in Keene, New Hampshire, has an inflow of 58,000 vehicles per day, a higher
traffic volume than the predicted traffic volumes at this intersection in 2030.
Trip Distribution
The trip distribution on Page 19 of the Traffic Study found that there is an error in the trip
distribution at the West Reserve Drive/Whitefish Stage Drive intersection. The predicted
distribution is 5 percent north, 15 percent west, and 5 percent east to north, but 25 percent enter at
Access C. a 10 percent increase over the 10 percent westbound traffic at the intersection.
Additionally there are variations in the site -generated traffic. For instance 888 vehicles exit left
from Access Road C to West Reserve Road, but only 533 vehicles reach Whitefish Stage Road, 350
vehicles disappear. Site generated traffic in Figure 9 shows 482 vehicles are westbound on West
Reserve at Whitefish Stage Road but 803 turn right into Access C. That means that some 321
vehicles appear out of thin air.
Much of Kalispell has a historic grid network that provides drivers with alternate routes and the
opportunity to balance their trip distance and trip time. Unfortunately, destruction of the grid and
concentration of traffic and reduced driver options is occurring by the permitting of "islands of
development" that do not adequately provide for connectivity to and expansion of a grid net work
of streets needed to contain and reduce traffic impacts as Kalispell grows. Enhancing the existing
arterial grid by adding to the intermediate grid network and by replacing signalized intersections
with modern roundabouts, Kalispell can realize significant capacity increases, which are achievable
at a much lower cost than widening roads to accommodate signalized intersections. Not only can
roundabouts accommodate up to 30 percent higher volumes with fewer lanes and fewer and less
severe crashes, they require almost no maintenance.
Capacity Analyses
Included within the capacity analyses are a number of assumptions that others will construct a
number of necessary road projects but no mention is made about the impacts if those projects are
not funded. one assumption is that West Reserve Road will be widened to four lanes, including the
bridge over the rivers from US-93 to east of Whitefish Stage Road. In addition, the predicted traffic
volume westbound on West Reserve Road, east of Whitefish Stage Road is more than a two-lane
road can accommodate. Therefore, widening of West Reserve Road from. US-93 to US-2 is essential
to this development. However, widening of West Reserve Road to four lanes is inadequate.
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Analyses on Pages C-72IC-73 show that this widened road will fail, LOS E on both sections of
Whitefish Stage Road with queues so long they cannot be determined. Widening of West Reserve
Road at US-93 is inadequate, as the intersection will fail before 2030 with four of the 12
movements at LOS E and 4 movements with infinite queues. If this road and bridge widening does
not occur in the near future what are the implications for traffic flow in this area. Where will the
large increase in traffic go and what impact will that have on other roads`?
Summary
There are a number or issues of concern regarding the distribution of traffic, the choice of all -red
time, non inclusion of pedestrian facilities at the signalized intersections, 95th percentile vehicle
queues that may be infinite or exceed the listed values, and the significant number of vehicle
movements at LOS E. especially several through movements that need to be addressed.
A redesign of the Bypass to a true Bypass Road that merges with to US-93, absent an at -grade
signalized intersections, with the north connection north of Rose Crossing so that its capacity is not
reduced to less than 40 percent by at grade signalized intersections is needed.
Upgrading and extending the existing road grid network is also needed where narrower roads with
roundabout control can provide a far safer, economical network to service this and future
developments while providing drivers with a choice of routes.
Sincerely,
Alternate Street Design, P.A.
Michael J. Wallwork, P.E.
President
R
Victoria Transport Polio/ Institute
Website: www.vtpi.org Email: info@vtpi.org
1250 Rudlin Street, Victoria, BC, V8V 3R7, CANADA
Phone & Fax 250-360--1560
"Efficiency - Equity - ClariV
Traffic Calming
Benefits, Costs and Equity Impacts
by
Todd Litman
Victoria Transport Policy Institute
7 December, 1999
Abstract
This paper describes a framework for evaluating traffic calming programs. Potential
benefits include road safety, increased comfort and mobility for non -motorized travel,
reduced environmental impacts, increased neighborhood interaction, and increased
property values. Traffic calming can help create more livable communities and reduce
suburban sprawl. Traffic calming costs can include project expenses, liability claims,
vehicle delay, traffic spillover, problems for emergency and service vehicles, driver
frustration, and problems for bicyclists and visually impaired pedestrians.
Traffic calming tends to provide the greatest benefits to pedestrians, bicyclists and local
residents, while imposing the greatest costs on motorists who drive intensively (i.e., as fast
as possible}. Traffic calming tends to increase horizontal equity by reducing the external
costs imposed by motor vehicles and improving the balance between different uses of
public streets. Traffic calming tends to increase vertical equity because it benefits people
who are physically, economically and socially disadvantaged, while imposing the greatest
disbenefits on relatively wealthy, higher mileage drivers.
Each traffic calming project is unique, so each project should be evaluated individually. It
is important to avoid double counting. Sensitivity analysis can be used to test whether
conclusions are reliable under a range of possible scenarios.
0 1997-1999
Toad Alexander Litman
All Rights Reserved
Traffic Calming Benefits, Costs and Equity Impacts
Introduction
During the last century roads have been widened and straightened to accommodate more
and faster vehicle traffic. These changes facilitate driving but often degrade conditions for
walking, cycling, and for nearby residents. Even during the early years of motor vehicle
use some neighborhoods resisted increased traffic,' and this opposition has increased in
recent years.2
Traffic calming is the name for road design strategies to reduce vehicle speeds and
volumes.' There are many potential traffic calming strategies, as indicated in Table I.
Traffic calming projects can range from a few minor changes to neighborhood streets to
major rebuilding of a street network. Impacts range from moderate speed reductions on
residential streets, to arterial design changes,`' and woonerfs (residential streets with
minimal traffic speeds).s Traffic calming is becoming well accepted by transportation
professional organizations and urban planners.
Some people love traffic calming, some hate it, and others have mixed feelings. Advocates
argue that traffic calming protects residents, pedestrians and bicyclists from externalities
imposed by motor vehicle traffic, and allows residential and commercial streets to better
balance their multiple uses. Critics argue that it wastes resources, that it imposes an unfair
burden on drivers, that it simply shifts traffic impacts from one street to another, and that
it does more harm than good.'
Many of the concerns about traffic calming relate to specific devices, such as speed humps
or chokers, rather than the general concept of changing street designs to reduce traffic
speeds. These can often be addressed by expanding the range of strategies considered and
using the most appropriate strategy in each particular situation.
This paper provides a comprehensive framework for evaluating the benefits and costs of
traffic calming programs. This can help determine whether traffic calming is justified,
improve project designs, and identify who should bear project costs.
' Stephen Goddard, Getting There, Basic Books (New York), 1994.
David Engwicht, Reclaiming our Cities and Towns; Better Living with Less Traffic, New Society
Publishing (Philadelphia; www.slonet.orgL--�.canderso/dec.htmi), -�canderso/dec.htmi), 1993.
Ian Lockwood, "ITE Traffic Calming Definition," ITE Journal, July 1997, pp. 22-25.
4 Dan Burden and Peter Lagerwey, Road .Diets; Fixing the Big Roads, Walkable Communities
www.walkable.or ), 1999; Ian Lockwood, "A Traffic Calming Plan for Route 50," Transportation
Planning, American Planning Association, Vol. 23, No. 3, Fall 1997, pp. 1-8.
5 Eran Ben -Joseph, "Changing the Residential Street Scene: Adapting the Shared Street Concept to the
Suburban Environment," Journal of the Am. Planning Asso., Vol. 61, No. 4, Autumn 1995, pp. 504-515.
b Wolfgang Homburger, et al., Residential Street Design and Traffic Control, ITE (Washington DC;
www.ite.or ), 1989; Residential Streets, American Society of Civil Engineers and National Association of
Home Builders (Washington DC), 1990; Canadian Guide To Traffic Calming, TAC (Ottawa; www.tac-
atc. ca), 1999.
7 Say "ND" to Traffic Obstruction!, National Motorists Association ( ww.motorists.com); Americans
Against Traffic Calming (www.io.com/—bumper/ada.htm). er/ada.htm).
Traffic Calming Benefits, Costs and Equity Impacts
Table 1 Menu of Traffic Calming Strategies and Devices'
Type
Description
Applications
Impacts
Arterials
Local
Volumes
S eds
Speed limits
Reduced speed limits.
V
V/
Yes
Yes
Speed alert,
enforcement
Radar -clocked traffic speeds displayed to drivers. strong speed
limit enforcement.
V
No
Yes
Vehicle restrictions
Limiting vehicle types (trucks) or users (residents only) on
specific roads.
.I
.I/
Yes
No
Warning signs and
gateways
Signs & gateways indicating changing road conditions, traffic
calming, residential or commercial districts.
,r
No
Yes
Speed tables, raised
crosswalks
Ramped surface above roadway, 7-1 o cm high, 3-6 in long.
With
caution
V
Possible
Yes
Median island
Raised island in the road center (median) narrows lanes and
provides pedestrian with a safe place to stop.
,/
V
No
Yes
Channelization islands
A raised island that forces traffic in a particular direction, such
as right -turn -only.
.e'
Possible
Yes
,,Speed hums
Curved 7-10 cm high, 3-4 m long hump.
V
V/
Possible
Yes
Rumble Strips
Low bumps across road make noise when driven over.
V
No
Yes
Mini -circles
Small traffic circles at intersections.
Possible
Yes
Roundabouts
Medium to large circles at intersections.
✓
Yes
Pavement treatments
Special pavement textures (cobbles, bricks, etc.) and markings
to designate special areas.
✓
Not
Likely
Yes
Bike lanes
Marking bikelanes narrows traffic lanes.
No
Possible
Curb extensions
bulbs, chokers .
Extending curb a half -lane into the street to controi traffic and
reduce pedestrian crossing distances.
Possible
Yes
"Road diets"
Reducing the number of traffic lanes.
V
Yes
Yes
Lane narrowings,
"pinch oints"
Curb extensions, planters, or centerline traffic islands that
narrow traffic lanes. Also called "chokers."
✓
Not
Likely
Yes
Horizontal shifts
Lane centerline that curves or shifts.
V
No
Yes
Chicanes
Curb bulges or planters (usually 3) on alternating sides,
forcing motorists to slow down.
✓
Possible
Yes
2-lanes narrow to 1-
lane
Curb bulge or center island narrows 2-lane road down to 1-
lane, forcing traffic for each direction to take turns.
V
Possible
Yes
Semi-diverters, partial
closures
Restrict entry/exit to/from neighborhood. Limit traffic flow at
intersections.
V
Yes
Possible
Street closures
Closing off streets to through vehicle traffic at intersections or
midblock
Yes
Yes
Sto si s
Additional stop signs, such as 4-way-stop intersections.
V
Possible
Yes
"Neotraditional"
street desi2
Streets with narrower lanes, shorter blocks, T-intersections,
and other design features to control traffic speed and volumes.
V
V
yes
Yes
TDM
Various strategies to reduce total motor vehicle use.
V1
yes
No
Woonerf
Very low -speed residential streets with mixed vehicle and
pedestrian traffic.
I
V
Yes
Yes
This table summarizes common traffic calming strategies and devices, indicating suitable
applications and impacts. Traffic calming projects often involve several measures.
8 Based on Carman Hass-Klau, et al, Civilised Streets; A Garde to Traffic Calming, Environmental and
Transport Planning (Brighton, UK), 1992; Joseph Savage, R. David MacDonald and John Ewell, A
Guidebook for Residential Traffic Management, WSDDT (Olympia; www.wsdot.wa.gov), 1994; Making
Streets that Work, City of Seattle (www.ci.seattle.wa.us/npo/tblis.htm), 1996; Pat Noyes, Traffic Calming
Primer, Pat Noyes & Associates (Boulder; pat , 3a,pdpro .corn), 1998.
Traffic Calming Benefits, Costs and Equity Impacts
Traffic calming design is an art and science. Some strategies, such as four-way stopsigns,
quickly lose their effectiveness without strict enforcement. Vehicle restrictions (such as
prohibiting trucks on a particular road) may raise legal and logistical issues. Because of
possible spillover effects (discussed later in this paper) it may be important to implement
an overall traffic management plan, which includes traffic calming.
Roundabouts & Traffic Circles
There are three types of roundabouts (also called "traffic circles").
1. Big old ones, such as Picadilly Circus in London and Dupont Circle in Washington DC, which
have lots of traffic lanes, lots of confusion, and lots of problems for drivers, cyclists and
pedestrians. They exist primarily to provide a dramatic site for a large monument.
2. Modern Roundabouts, are modest in size, are limited to a single circular traffic lane, and require
vehicles entering that lane to slow to about 15 mph maximum and yield. They are widely promoted
by traffic engineers as an efficient and safer alternative to signaled intersections.
3. Mini Roundabouts, are small (usually 10-25 feet in diameter) traffic circles placed in existing
low -volume intersections as traffic calming devices. They reduce traffic speeds and crashes.
Traffic calming can be incorporated into new developments using "neotraditional"
neighborhood street design. This uses a network of trough streets (as opposed to a
hierarchical road system with many dead end streets and cul de sacs) with narrow street
widths, shorter block lengths, "tee" intersections, and other design features to control
vehicle speeds and volumes.9 Table 2 summarizes typical street dimensions for
neotraditional neighborhoods, which are much narrower than has been used in most new
developments during the last half century.
Table 2 Narrow Residential Street Standards From Selected Communities'o
city
Street Tjpe
ROW
Width
Parking
Direction
Pord and, OR
a Dead End Streets <3 00' 1 on
3 5'
18'
None
2-wa
b< 9 units Er acre
35'
20'
1-side
2-way
c Standard Residential NNUM00100M
ownMadison,
24'
'2-sides
2-wax
WI
a <3 units per acre
EXON"M40'*
40'
27'
2-sides.
2-wa
b 3-10 units per acre
56'
28'
2-sides
2-way_
Novato, CA
a Serves 2-4 dwellin s
25'
20'
2-sides
2-way
b Serves 5-15 dwellings
40'
28'
2-sides
2-way
San Jose, CA
[ins cified
50'
24'-36' * *
2-sides
2-way
Dublin, CA
Unspecified
50'
26'-36'***
2-sides
2-way
56' with sidewalks * * Narrows to 24' at tree planters forming parking bays.
* * * Two opposing five foot wide tree planters located every 100' reduce the effective street width by 10'.
9 Dan Burden, Street Design Guidelines for Healthy Neighborhoods, Center for Livable Communities,
Local Government Commission (Sacramento; www.ljzc.org/cic), 1999.; Traditional Neighborhood
Development Street Design Guidelines, Institute of Transportation Engineers, Publ. No. RP-027
(Washington DC; www.it, 1998.
}° J. Kevin Keck, Caught in the Middle: The Fight for Narrow Residential Streets, Proceedings of the ITE
14th International Conference, 1998.
Traffic Calming Benefits, Costs and Equity Impacts
Estimating Travel Impacts
An important factor in evaluating traffic calming projects is the number of trips that are
affected. The number of automobile trips affected is usually easy to determine since most
communities have good motor vehicle traffic data. It may be more difficult to determine
the number of non -motorized trips affected because they are usually undercounted.
Some travel surveys exclude non -motorized trips altogether, and when included they are
undercounted because walking and cycling trips are often short, non -work, recreational
trips, or involve children. Automatic traffic counters do not record non -motorized travel,
and manual counts usually focus on arterial streets, ignoring popular walking and cycling
routes on minor streets. walking and cycling links of trips involving a motor vehicle are
also ignored. For example, `walk -auto -walk," or "walk -transit -walk" trips are usually
classified simply as "auto" or "transit," even if walking takes place on a roadway. Extra
effort is needed to gather accurate data on non -motorized travel.
There is considerable latent demand for non -motorized travel. That is, people would walk
and bicycle more if they had suitable conditions. One market survey found that 80% of
Canadians would like to walk more, and 66% would like to cycle more than they currently
do." A Harris poll found that 70% of U.S. adults want better facilities for non -motorized
transport. 12 Communities and shopping districts that accommodate non -motorized
transportation are popular with residents and customers.
Improving pedestrian security (protection from accidents and crimes) is important for
increasing travel choices." Traffic calming can be an important part of Transportation
Remand Management (TDM) programs by creating streets that are more suitable for
walking, bicycling and public transit.14 Transit and rideshare passengers rely on walking or
cycling for mobility at their destinations.
A grid -street network reduces trip distances and congestion by providing more direct
routes then a branched street network that concentrates all traffic on a few routes. But
many people prefer living on a cul de sac rather than a through street to avoid traffic
impacts. Traffic calming allows communities to have the best of both worlds: a grid street
network with limited traffic speeds and volumes. This allows older urban neighborhoods
to have attractive street environments that are otherwise only be available in more
automobile -dependent suburban locations. Traffic calming is therefore key to creating grid
street patterns and encouraging urban inf ll, both of which reduce automobile use.
Environics, .National Survey on active Transportation, Go for Green, wtiww. ofor een.ca), 1998.
' Cited in Trails far Transportation, National Bicycle and Pedestrian Clearinghouse Technical Assistance
Series, Number 3 (www.bikeped.org), 1995.
13 Social Research Associates, Personal Security Issues in Pedestrian Journeys, UK Department of the
Environment, Transport and the Regions (London; www.mobility-unit.detr.gov..uklpsi), 1999.
1
4 Todd Litman, Potential TDM Strategies, VTPI (www.ytpi.org), 1999.
' 5 Reid Ewing, Best Development Practices, Planners Press www. tannin .or ), 1996.
Traffic Calming Benefits, Costs and Equity Impacts
Table 3 Daily Trips Per Household 16
Rural
Suburban
Urban
Avera e
Walk
0.4
0.4
1.8
0.6
Bicycle
0.1
0.1
0.1
0.1
Total Non -Motorize
0.5
0.5
1.9
0.7
Transit
0.3
0.3
1.1
0.4
Auto Passen er
3.5
2.7
2.8
2.7
Auto Driver
7.8
6.6
6.3
6.4
Total, All Modes
12.2
10.1
12.1
10.1
Residents in neighborhoods with suitable street environments tend to walk and bicycle
more," ride transit more,18 and drive less than comparable households in other areas.'9
One study found that residents in a pedestrian friendly community walked, bicycled, or
rode transit for 49% of work trips and 15% of their non -work trips, 18- and 11-
percentage points more than residents of a comparable automobile oriented community.'o
Another study found that walking is three times more common in a community with
pedestrian friendly streets than in otherwise Comparable communities that are less
conducive to foot travel.21 U.S. Households average 0.7 non -motorized trips per day
overall, but more than twice this amount in urban neighborhoods, which tend to be more
suitable to walking, as indicated in Table 3, and Figure 1.
In recent years various techniques have been developed to help evaluate pedestrian and
cycling conditions and predict the effect of changes on non -motorized travel. For
example, the Bicycle Compatibility Index developed for the Federal Highway
Administration can be used to evaluate the benefits to cycling that result from changes in
road and traffic conditions. Similarly, the Pedestrian Environmental Factor (PEF) can be
14
used to assess conditions for pedestrians.
16 1995 National Personal Transportation Survey, USDOT www-eta.oml. ovlc iln is .
" Rhys Roth, Getting People Walking: Municipal Strategies to Increase Pedestrian Travel, WSDOT
(Olympia; www.wsdot.wa.gov/ta/t2/t2pubs.htm), 1994.
118 Project for Public Spaces, Transit -Friendly Streets: Design and Traffic Management Strategies to
Support Livable Communities, TCRP Report 33, TRB (Washington DC; www.nas.edu/trb), 1998.
Parsons Brinckerhoff, The Pedestrian Environment, 1000 Friends of Oregon (Portland;
www.telqlort.com/-friends), 1993; Andrew Clarke, Traffic Calming, Auto -Restricted Vanes and other
Traffic .Management Techniques: Their Effects on Bicycling and Pedestrians, National Bicycling and
Walking Study, # 19, FHW.A (Washington DC; www.bikefed.or ), 1994.
2° Robert Cervero and Carolyn Radisch, Travel Choices in Pedestrian Versus Automobile oriented
Neighborhoods, UC Transportation Center, UCTC 281(http://_socrates.berkeley.edu/-uctc} 1995.
21 Anne Vernez Moudon, et al., Effects of Site Design on Pedestrian Travel in Mixed Use, Medium -
Density Environments, Washington State Transportation Center (Seattle), 1996.
22 BicyclelPedestrian Trip Generation Workshop: Summary, FHWA (www.tfhrc.gov), 1996.
2� David L. Harkey, Donald W. Reinfurt, J. Richard Stewart, Matthew Knuirnan and Alex Sorton, The
Bicycle Compatibility .Index: A Level of Service Concept, Federal Highway Administration
(www.hsrc.unc.edu/researchlpedbikelbci}, 1998.
24 PBQD, The Pedestrian Environment, 1000 Friends of Oregon (www.telep2rt.com/-friends) 1993.
5
Figure I
Traffic Calming Benefits, Costs and Equity Impacts
Average Daily Trips Per Household by Neighborhood Type25
12
a�
a. 10
N
CL
H. S
0
6
W 0 4
� 2
a
Suburban Traditional
■Walk
❑ Bicycle
❑Transit
El Auto Passenger
IN Auto Driver
Vehicle trips per household are significantly higher in suburban communities due to
lower densities and fewer travel choices.
If more precise modeling is not feasible, a reasonable assumption is that traffic calming
which significantly improves walking and cycling conditions can increase non -motorized
trips in an area by 1 o-20% from what would otherwise occur, and that half of these trips
substitute for motor vehicle trips. Thus, if per household non -motorized trips currently
average 1.8 per day (typical in urban neighborhoods), comprehensive traffic calming could
increase this to 2.0-2.2, and reduce 0.1-0.2 motor vehicle trips per day.
The following factors influence how much a traffic calming project will affect travel:
• Magnitude of change. The more traffic calming improves pedestrian and cycling conditions,
the more it will affect travel. Traffic calming that significantly reduces a barrier to non -
motorized travel (for example, by making it easier to walk across an arterial from one major
commercial center to another or creating a pleasant bicycle travel corridor where none
otherwise exists) may have significant travel impacts in an area.
• Demand. A greater effect is likely to occur where traffic calming is implemented near major
pedestrian and cycling generators: residential neighborhoods, commercial centers, schools, and
recreation centers.
• Integration with other improvements. Traffic calming can have synergetic impacts with other
Transportation Demand Management (TDM) and land use changes that support walking,
cycling and transit.. For example if traffic calming is implemented with sidewalk and bikepath
improvements, parking management, and improved public transit service, the effects are often
greater than the sum of what individual strategies could achieve.
+ Land use effects. Over the long term, traffic calming can support land use patterns that further
reduce automobile use and automobile dependency, such as more neighborhood shops and
activity centers.
2$ Bruce Friedman, Stephen Gordon, John Peers, "Effect of Neotraditional Neighborhood Design on
Travel Characteristics," Transportation Research Record, #1466, 1995, pp. 63-70.
Traffic Calming Benefits, Costs and Equity Impacts
Benefits and Costs
This section explores benefits and costs that frequently result from traffic calming.
Benefits
1. Increased Road Safety
Reducing traffic speeds and volumes can reduce the severity and severity of vehicle
crashes, particularly those involving pedestrians and bicyclists. 26 Each 1--mph traffic speed
reduction typically reduces vehicle collisions by 5%, and fatalities by an even greater
amount.' Travelling at 40 mph, the average driver who sights a pedestrian in the road 100
feet ahead will still be travelling 38 mph on impact: driving at 25 mph, the driver will have
stopped before the pedestrian is struck."
Pedestrian injury severity increases with the square of vehicle speed, as indicated in Figure
I . The probability of pedestrians receiving fatal injuries when hit by a motor vehicle is
3.5% at 15 mph, 37% at 31 mph and 83% at 44 mph .29 Researcher Gary Davis developed
a method for predicting pedestrian accident and injury risk.°
Figure I Impact Speed Versus Pedestrian Injury'
10 14 18 22 26 36 34 38
Vehicle Miles Per Hour
Risk to pedestrians and cyclists increases with traffic speed.
26 C.N. RIoeden, A.J. McLean, V M. Moore and G . Ponte, Travelling Speed and the Risk of Crash
Involvement, NHMRC (Adelaide; http://plato.raru.adelaide.edu.au/s eediindex.htmi), 1998; Jack Stuster
and ZaiI Coffman, Synthesis Of Safety Research Related To Speed And Speed Limits, FHWA No. F14WA-
RD-98-154 (www.tfhrc.gov/safely/spged/speed.htm), 1998; "Pedestrian Safety," Oregon Bicycle and
Pedestrian Plan, Oregon DOT (www.odot.state.or.us/techserv/bikewalk/planimaedestrn.htm .
1' D.J. Finch, P. Kompfner, C.R. Lockwood and G. Maycock, Speed, Speed Limits and Accidents,
Transport Research Laboratory www.trl.co.uk), Report 58, 1994,
28A.J. McLean, RWG Anderson, MJB Farmer, BH Lee and CG Brooks, Vehicle Speeds and the Incidence
of Fatal Pedestrian Collisionsµ Volume 1. Federal Office of Road Safety, Australia. Rudolph Limpert, Motor Vehicle Accident Reconstruction and Cause Analysis, Fourth Edition, Michie
Company,. Charlottesville, 1994, p. 663.
30 Gary Davis, "Method for Estimating Effect of Traffic Volume and Speed on Pedestrian Safety for
Residential Streets," Transportation Research Record 1636, 1998, pp. 110-115.
3' Traditional Neighborhood Development Street Design Guidelines, Institute of Transportation
Engineers (Washington DC; www.ite.o), June 1997, p. 18.
Traffic Calming Benefits, Costs and Equity Impacts
How Quickly A Motorist Can Stop32
Take speed in MPH and multiply by 1.5 to get the approximate feet traveled per second. Drivers
typically require about 2.5 seconds to react to a hazard. At 40 MPH, that's 60 feet per second
travel speed, which requires about 150 feet of travel before the driver even steps on the brakes. The
faster a vehicle travels the longer its stopping distance and the greater its potential for causing
damage and injuries if it hits another road user.
Other researchers conclude that, "small reductions in traveling speed translate into large
reductions in impact speed in pedestrian collisions, often to the extent of preventing the
collisions altogether."" They predict that a 5 km/h reduction in urban traffic speeds could
reduce pedestrian fatalities by 30%. In 10% of cases the collisions would be avoided and
in 20% an otherwise fatal collision would become non -fatal, with comparable reductions in
severity for non -fatal accidents. The researchers find that limiting speed reductions to
residential areas would have a much smaller benefit, since more than 85% of fatal
pedestrian collisions occur on non -local roads such as arterials. Eliminating driving above
the posted speed limits would reduce an estimated 13% of pedestrian fatalities.
Another study using a database of 20,000 residential -area automobile accidents found that
crash rates (annual crashes per mile) increased as street width increased beyond 24-feet
between curbs, particularly on straighter streets with lower traffic volumes, where average
traffic speeds tend to be highest.34 The analysis indicates that accident rates are
approximately 18 times higher on a 48-foot width street compared with a 24-foot street.
With any traffic safety program it is important to consider the possibility of "offsetting
behavior." If drivers, bicyclists or pedestrians feel safer they may become less cautious and
"offset" a portion of crash reduction benefits.�$ It is therefore important to use empirical as
well as theoretical evidence to determine traffic safety effectiveness.
Experience indicates that traffic calming programs do significantly reduce traffic crash
frequency and severity.36 Studies show long-term crash and injury reductions of 15-40%,
" Michael Ronkin, Bicycle and Pedestrian Program Manager, Oregon Department of Transportation.
33 A.J. McLean, et al., "Vehicle Travel Speeds and the Incidence of Fatal Pedestrian Collisions," Accident
Analysis and Prevention, Vol. 29, No. 5, 1997, pp. 667-674.
34 Peter Swift, Residential Street Typology and Injury Accident Frequency, Swift and Associates
(Longmont), 31 March 1998.
35 Gerald Wilde, Target Risk, PDE Publications (Toronto; http:Ilpae.queensu.caltarget), 1994; Robert
Chirinko and Edward Harper, Jr., "Buckle Up or Slow Down? New Estimates of Offsetting Behavior and
their Implications for Automobile Safety Regulation," Journal of Policy ,analysis and Management, Vol.
12, No. 2, 1993, pp. 270-296.
36 Andrew Clarke, Traffic Calming, Auto -Restricted Zones and Other Traffic Management Techniques:
Their Effects on Bicycling and Pedestrians, National Bicycling and Walking Study, # 19, FHWA
(Washington DC; www.bikefed.oEg), 1994.
8
Traffic Calming Benefits, Costs and Equity Impacts
and even greater reductions in pedestrian injuries.' One recent before -and -after study
found that traffic calming reduced collision frequency by 40%, vehicle insurance claims by
3 8°fin, and fatalities from one to zero.38 This provided a very favorable six-month payback
on project expenses from insurance claim savings alone.
Similarly, a study of 119 residential traffic circles installed in the city of Seattle between
1991 and 1994 found that reported accidents in those areas declined from 187 before
installation to 11 after installation, and injuries declined from 153 to one. Portland,
Oregon found similar safety benefits.44 A review of 600 Danish traffic calming projects
found an average 43% reduction in traffic crash casualties .4' Similar reductions in
accidents are reported in other studies, as indicated in Figure 2.
Figure 2 Reported Traffic Calming Accident Reductions4
100%
,C
80%
.... F
60%
� 40°IQ
C. -a 20%
�8
a 0%
Fifteen International Studies
This figure illustrates changes in vehicle accident rates from traffic calming programs
reported in fifteen international studies, indicating that most show significant reductions.
Quantifying Safety Benefits
Studies described above indicate that traffic calming which significantly reduces traffic
speeds typically reduces crashes by 40%, although impacts vary depending on other
factors. Historical accident data can be used to determine the frequency of crashes on the
roads to be calmed, beeping in mind that many crashes (particularly those involving
pedestrians and cyclists) are not reported to police.43 An alternative approach is to use
national crash rate data for urban streets in Table 4.
37 Steve Proctor, "Accident Reduction Through Area -wide Traffic Schemes," Traffic Engineering &
Control, Vol. 32, No, 12, Dec. 1991, pp. 566-572.
3 s Sany R. zein, Erica Geddes, Suzanne Hemsing and Mavis Johnson "Safety Benefits of Traffic
Calming," Transportation Research Record 1578, 1997, pp. 3-10.
39 James Mundell, "Neighborhood Traffic Calming: Seattle's Traffic Circle Program," Road Management
& Engineering Journal www.usroads.coral'oumals/rme'198U I Irm980102.htm , January 1998.
a° See www.trans .ci. portland. or. uslTraff.c ManNement/trafficcalming/reports/accidents.htm.
41 T. Harvey, A Review of Current Trajjzc Calming Techniques, Institute of Transport Studies (Leeds,
www.its.leeds.ac.uk/t)rimavera/p calmin .html#a41 ), 1991.
42 Hamilton Associates, Safety Benefits of Traffic Calming, Insurance Corporation of British Columbia,
(Vancouver), available from the Road Safety Group www.roadsafe .com), 1996, Figure 3.2.
43 Helen James, "Under -reporting of Road Traffic Accidents," Traffic Eng+Corr, Dec. 1991, pp. 574-583.
Traffic Calming Benefits, Costs and Equity Impacts
Table 4 Crash Rate on Lower -Speed Urban Streets (Per 100 Million Vehicle Miles)44
Fatalities
Persons
Injured
Serious
Injuries
Pedestrian
Fatalities
Pedestrian
In juries
PDOs
(estimate)
Minor Arterials
1.08
191
16.8
0.28
6.3
1,910
Collectors
1.48
161
19.5
0.21
8.9
1,610
Local
1.17
311
32.9
0.37
18.6
3,110
As an analytic tool, accident costs are often monetized (measured in monetary units).¢5
Although human life is not a commodity, many financial decisions involve marginal
changes in the risk of injury and death. For example, consumers must decide whether to
purchase optional safety equipment such as vehicle air hags, and society must decide
whether to mandate such equipment. These tradeoffs are used to identify the value society
places on risk reduction.46 Table 5 shows values used by the U.S. Federal Highway
Administration. Some state and provincial transportation agencies have developed their
own values. Table 6 illustrates typical monetized traffic calming road safety benefits. This
analysis indicates that traffic calming can provide road safety benefits typically worth 6-
12¢ per vehicle mile if it reduces crash damages by 40%.
Table S FHWA Accident Costs Per Injury (1994 dollars)47
KABC Scale
Abbreviated lnj*u_q Seale AIS
Severity
Descriptor
Cost ($2
Severity
Descriptor
Cost M
K
Fatal
200,000
AIS 6
Fatal
2,600,000
A
Incapacitating
1803000
AIS 5
Critical
1,980,000
B
Evident
365000
AIS 4
Severe
4903,000
C
Possible
19,000
AIS 3
Serious
150,000
PDO
Pro2elly Damage Qnl Lf
200
AIS 2
Moderate
40,000
AIS I
Minor
51P000
Table 6 Monetized Traffic Calming Road Safety Benefitsas
Fatality
Cost at
Injury
Cost at
PDO
Cost at
Total
Traffic
Rate*
$3 million per
Rate*
$50,000 Per
Rate*
$2,500 Per
Crash
Calming
Fatality
Injury
PDO
Costs
Savings
Minor
Arterials
1.08
3.2 /mile
191
9.6 /mile
1,910
4.8 /mile
17.6¢ /mil
7.0 /mile
Collectors
1.48
4.40 /mile
161
8.10 /mile
1,610
4.00 /mile
16.50 /mile
6.60 /mile
Local
1 1.17
3.5¢ /mile
311
15.6/mile
3,110
7.80 /mile
126.80 /mi]S
10.70 /mile
* Per 100 million vehicle miles.
44 Highway Statistics 1996, FHWA (www.fhwa.dot/ ov/ohir /1996), 1997, Table FI-1). PDO crash rates
are estimated based on 10 PDO crashes for each injury crash.
45 Lawrence Blincoe, Economic Cost of Motor Vehicle Crashes 1994, NHTSA, USDOT (Washington DC;
www.nhtsa.doc.gov/people/economic/ecomvc 1994.htm1), 1995.
46 Ted Miller, The Costs of Highway Crashes, FHWA (Washington DC), FHWA-R.D-055, 1991.
47 Homberger, et al, Fundamental of Traffic Engineering, 14th Edition, Institute of Transportation Studies
(Berkeley), UCB-ITS-CN-96-1, 1996, p. 9-13.
48 Crash rate data from Table 2. Assumes traffic calming reduces crashes, injuries and fatalities by 40%.
10
Traffic Calming Benefits, Costs and Equity Impacts
Arterial Traffic Calming Success Story
Bridgeport Way W. is a principal arterial that carries 25,000 vehicles a day. It has two travel lanes
in each direction with a middle two -way -left -turn lane. Before the road improvements, there were
over 160 accidents less than a mile long section of this road for a three year period. We improved
this roadway by building curb, gutter, sidewalk, bike lanes, street lights, pedestrian crosswalks,
landscaped median and planter strips. We eliminated two -way -left turn lane with a landscaped
median and provided U-turn capabilities at intersections for passenger vehicles only.
The results of our study show that the both accidents and the speed dropped on this roadway after
we built the improvements. We are very pleased to see that we have 70% less accidents on this
road now. This is a significant improvement.
When we replaced the two -way -left -turn lane with a landscaped median, the local business owners
were very concerned. They did not believe people would drive an extra block to make U-turns to
access their businesses. Well, guess what'. I just asked our Finance Department to get me a City
wide sales tax information. We are collecting 5% more sales tax this year than previous year on a
city wide basis. But what is interesting is that we are collecting 7% more sales tax from the
businesses around the Bridgeport corridor. We all know that the economy is good now, nation
wide. Our general sales tax increase is primarily due to the good economic conditions. We are not
claiming that our road project is the primary reason for sales tax increase. But what we are
claiming is that, our road project helped.
We, engineers, must think more than cars when we build road projects. We must consider the other
factors just as much important as the cars; community vision, pedestrians, economic vitality,
bikers, joggers, etc. We all love to talk about vibrant communities. What better way to start
building a vibrant community than building a well balanced road projects!
Isn't it where it all starts from? Look around you, you can easily connect a poor road design and
construction with the poverty, isolation, community deprivation, frustration, high crime rates, etc.
We need to think differently. As someone stated oncec "we can not fix today's problems with the
same thinking that the created them in the first place." This is a very difficult concept for us,
engineers, to understand and translate into our road designs. Because, we are educated and trained
to move cars faster on wider roads.
I hope that your council will look at your road project from a broader perspective of what your
community will look like in the future rather than what specific engineering manuals or guidelines
to meet today. All design manuals and guidelines have enough flexibility for us to implement the
Council's vision. obviously, some of us are doing it, so should your engineers.
Ben Yazici
Assistant City Manager/Director of Public Works
City of University Place, Washington
II
Traffic Calming Benefits, Costs and Equity Impacts
2. Improved Conditions for Non -Motorized Modes
Traff c calming tends to improve pedestrian and cycling conditions.g Reduced vehicle
traffic speeds and volumes tend to make walking"' and cycling " safer, more comfortable
and more convenient. Many people place a high value on street design features that
improve safety and mobility for non -motorized transportation.12 A 1995 Harris poll found
that 70% of U.S. adults want better local facilities for non -motorized transportation.53 A
market survey found that 80% of Canadians would like to walk more, and 66% would like
to cycle more than they currently do.54 Many homebuyers want residences in
neighborhoods with narrow streets that limit vehicle traffic.""
Before Walt Disney Corporation built Celebration, its new town in Florida., they conducted an
extensive market study of what homebuyers wanted. Focus groups revealed that one out of
every two Americans wanted to live in a village -style or traditional neighborhood. However,
since less than one percent of current new development is styled on older, traditional patterns, a
major demand for neighborhoods that retain old town living styles goes unfilled .1
Better walking and cycling conditions are particularly important for people with
disabilities, the elderly, and children, who are more dependent on non -motorized travel,
and often have difficulty crossing busy traffic. As the population ages, a greater portion of
urban residents are likely to walk and cycle for transportation and recreation.
Quantifting This Benefit
The number of trips that benefit from traffic calming can be estimated based on local travel
data, as described earlier. These benefits can be monetized by asking residents how much
they value improved walking and cycling conditions. For example, a survey might
investigate how much residents would willingly pay for a significant improvement in
pedestrian and walking conditions on their street or in their neighborhood. Some transport
agencies place a dollar value on the delay and reduced mobility by walking and cycling
resulting from heavy vehicle traffic."'
49 Rhys Roth, Getting People Walking: Municipal Strategies to Increase Pedestrian Traver, WSDOT
(Olympia; www.wsdot.wa.gov/ta/t2/t2pubs.htm), 1994.
50 Ellen Vanderslice, Portland Pedestrian Design Guide, Pedestrian Transportation Program, City of
Portland (503-823-7004; wwvv.trans.ci. ortland.or.us), 1998.
5' David L. Harkey, Donald W. Reinfurt, J. Richard Stewart, Matthew Rnuiman and Alex Sorton, The
Bicycle Compatibility Index: A Level of Service Concept, Federal Highway Administration
www.hsrc.unc.edu/researchl dbikelbci , 1998.
" Daniel Carlson, Lisa Wormser and Cy Ulberg, At Road's End: Transportation and Land Use Choices
for Communities, Island Press (Washington DC; www.islandpress.org), 1995.
53 Cited in Trails for Transportation, National Bicycle and Pedestrian Clearinghouse Technical Assistance
Series, Number 3 (www.bikeped.org), 1995.
54 Environics, National Survey on Active Transportation, Go for Green, (www. o,for een.ca), 1998.
ss "Neighborhoods Reborn," Consumer Reports, May 1996, pp. 24-30.
56 Dan Burden, Street Design Guidelines for Healthy Neighborhoods, Center for Livable Communities,
Local Government Commission (Sacramento; www.1gc.org; cic), 1999.
5' Donald Rintoul, Social Cost of Transverse Barrier Effects, Planning Services Branch, B.C. Ministry of
Transportation and Highways (Victoria; www.th.gov.bc.ca/bchi ), October 1995
12
Traffic Calming Benefits, Costs and Equity Impacts
3. Increased Non -Motorized Travel And Reduced Automobile Travel
As described earlier, traffic calming can increase walking, bicycling and public transit use,
and reduce automobile travel. This provides both internal benefits (to people who increase
their non -motorized travel and reduce their driving) and external benefits (to others), as
summarized in Table 7. These benefits are not limited to the streets being calmed. If traffic
calming reduces a bottleneck on a cycling route, or improves access to public transit it can
result in mode shifts that reduce vehicle traffic on other roads.
Table 7 Benefits of Increased Non -Motorized Travel"
User Internal Benefits
External Benefits
Reduced congestion
Reduced road and parking facility expenses
Financial savings
Reduced accidents
Health benefits
Reduced pollution
Increased mobility for non -drivers
Resource conservation
En' o ment
Increased travel choices reduced automobile dependency)...
Increased walking and bicycling can improve health through aerobic exercise." A
sedentary lifestyle has a cardiovascular risk equal to smoking Zo cigarettes a day.60 This
exercise benefits children's physical and intellectual development, and parents who are
otherwise required to chauffeur children.6' Traffic calming can help reduce automobile
dependency (high levels of automobile use, limited travel choice for non -drivers, and
automobile oriented land use patterns) and its associated costs.62
Although walking and bicycling are often slower than driving, a voluntary shift to non -
motorized travel can be assumed to provide net user benefits. In other words, if traffic
calming allows people to shift from driving to walking or bicycling, any increase in time
does not represent a net cost to users since they would not otherwise make that choice.
Many people enjoy time spent walking and cycling, or value it as a form of exercise.
Quantifying These Benefits t
Studies described earlier in this report indicate that traffic calming can increase non -
motorized travel and reduce automobile travel, although actual impacts will vary
depending on many factors. A single traffic calming project is unlikely to have much effect
on total travel, but a comprehensive traffic calming programs that supports other
transportation demand management efforts may have very significant effects.
"$ Todd Litman, Guide to Calculating TDM Benefits, VTPI (www.ytyi.org}, 1997.
s9 Edmund Burke, Benefits of Bicycling and Walking to Health, National Bicycling and walking Study
# 1 4, USDOT, FHWA (Washington DC; www.bike ed.or ), 1992; Physical Activity Task Force, More
People, More Active, .More often, UK. Department of Health (London), 1995.
60 Ian Roberts, et al., Pedalling Health --Health Benefits of a Modal Transport Shift, Bicycle Institute. of
South Australia (www.sci*ence.adelaide.edu.au/slate/demos/cyhealth.pdf). 1996.
61 Mayer Hillman, ed., Children, Transport and the Quality of Life, Policy Studies Inst. (London), 1993.
62 Peter Newman and Jeffery Kenworthy, Cities and Automohile Dependency, Gower (Aldershot), 1989;
Todd Litman, Automobile Dependency as a Cost, VTPI (www.yVi.org), 1996.
13
Traffic Calming Benefits, Costs and Equity Impacts
Vehicle travel reductions can be estimated using values of the elasticity of vehicle travel
with respect to travel time, which ranges from. about -0.2 in the short term up to -1.0 over
the long term.6' Thus, if a comprehensive traffic calming program reduces average travel
speeds by 10%, it can be estimated that total vehicle travel would decline 2% in the short
term and up to 10% over the long term.
Table 8 summarizes estimates of some benefits of a mode shift from driving to non -
motorized travel. These benefits tend to be greatest in urban areas where traffic calming
projects are most common. A reasonable estimate is that these benefits average about
$2.00 per urban trip shifted from driving to non -motorized travel.
Table 8 Savings Per Trip of Shift From Driving To Non -Motorized Travels4
Urban Peak
urban off -Peak
Rural
Con estion
$0.40
$0.04
$0.00
Road Costs
0.10
0.05
0.05
Parking
1.50
o.25
0.05
User Costs
0.85
0.55
0.55
Air Pollution
0.25
0.20
0.05
Noise
0.10
0.05
0.02
Load Safety
0.15
0.12
0.10
Additional Environmental & Social
0.23
0.23
0.23
Totals
$3. 58
,$1. 49
1 $1. 05
4. Noise, Air Pollution, and Aesthetics
Traffic calming generally reduces traffic noises Speed reductions from 50 to 30 kph
typically reduce noise levels by 4-5 decibels,6 or more in some circumstances.67 Strategies
that reduce traffic speeds to about 30 kilometers per hour and smooth traffic flow reduce
air pollution, while those that increase stops may increase emissions.
Actual impacts vary depending on specific conditions. Measures that cause more frequent
acceleration, and some textured road surfaces, can increase noise and air emissions. one
study found that installing six speed humps on a previously 40 krn/hr road increased NOx
emissions 10 times, CO emissions 3 times, and fuel consumption from 7.9 to 10 liters per
100 km. g Strategies resulting in constant, moderate speeds provide the greatest benefits.
63 Harry Cohen, `{Review of Empirical Studies of Induced Traffic," Curbing Gridlock, Appendix B,
National Academy Press (Washington DC; www.nas.edu/trb), 1994, pp. 295-309.
64 Todd Litman, Quantifying Bicycling- Benefits for Achieving TDM Benefits, VTPI (www.vtpi.org}, 1998.
65 Traffic Calming: Traffic and Vehicle Noise, Department of the Environment, Transport and the
Regions (UK.; www.roads.detr.pov.uk/roadnetwork/ditm/taUtraffic/06 961iteml.htm 111996.
66Tim Pharoah and John Russell, Traffic Calming: Policy and Evaluations in Three European Countries,
South Bank Polytechnic (London), February 1989.
67 Take Back .Your Streets, Conservation Law Foundation (Boston; www.clf.org), May 1995, p. 27.
61 Quoted in Daily Express (London), October 1995.
14
Traffic Calming Benefits, Costs and Equity Impacts
Table 9 summarizes air emission and fuel consumption impacts from typical traffic calming
speed reductions.
Table 9 Effects of 50 kph to 30 kph Speed Reduction69
"Easy" Driver
"Aggressive" Driver
Carbon monoxide
-13%
-17%
VoCs
-22%
-10%
NGx
-48%
-32%
Fuel use
-7%
+7%
Reduced traffic speeds reduces vehicle emissions and fuel consumption in most cases.
Traffic calming can help create more attractive urban environments.70 Commercial areas
along higher -speed streets tend to be unattractive because businesses must "shout" at
passing motorists with large signs, because so much land is used for parking, and because
settlement patterns have no clear form.'' Traffic calming projects sometimes reduce the
amount of land devoted to streets and parking.' This can increase greenspace and reduce
impervious surfaces, resulting in environmental and financial benefits (particularly reduced
stormwater costs).73
Quantifying These Benefits
Traffic noise and air emission models are available,'' but these are mostly designed for
highway conditions and are poorly calibrated for lower -speed travel. A better approach
would be to field test the effects of traffic calming. A number of monetized estimates of
automobile environmental costs are available, although many use nation-wide values that
tend to underestimate costs under higher -density urban conditions.'
69 Michael Replogle, "Minority Statement," Expanding Metropolitan Highways, Transportation Research
Board/National Academy Press (Washington DC; www.nas.edu/trb), 1995, p. 369.
'° Suzanne Crowhurst Lennard and Henry Lennard, Livable Cities Observed, Gondolier (Carmel) 1995.
' � William Shore, "Recentral ization; The Single Answer to More Than a Dozen United states Problems
and A Major Answer to Poverty," American Planning Assoc. Journ., Vol. 61, No. 4, Summer 1995, 496-
503.
12 Jim west and Allen Lowe, "Integration of Transportation and Land Use Planning through Residential
Street Design," ITE Journal, August 1997, pp. 47-51.
73 Chester Arnold and James Gibbons, "Impervious Surface Coverage: The Emergence of a Key
Environmental Indicator," Am. Planning Association Journal, Vol. 62, No. 2, Spring 1996, pp. 243-258;
NEMO project (www.lib.uconn.edu/CANR/ces/nemo/nnps.htmi).
74 Such as the EPA MOBILE model for (air (pollution, and the FHWA STAMINA model for noise.
75 Dr. Peter Bein, Monetization of Environmental Impacts of Roads, Planning Services Branch, B.C.
Ministry of Transportation and Highways (Victoria, www.th-gov.bc.ca/bchighwg1s), 1997; Todd Litman,
Transportation Cost Analysis; Techniques, Estimates and Implications, VTPI (www.y!I iLorg), 1998.
15
Traffic Calming Benefits, Costs and Equity Impacts
5. Increased Neighborhood Interaction and Crime Prevention
Public streets are an important component of the `public realm" where people can meet in
a neutral space. Street environment conditions affects how people interact in a community.
Traffic calming helps mare public streets lively and friendly, encourages community
interaction, and attracts customers to commercial areas .76 As traffic increased on a street,
residents tended to have fewer friends and acquaintances among their neighbors, and the
area they consider "home territory" declined."
Traffic calming is also used to discourage extreme anti -social behavior.' Neighborhoods
that are more difficult to drive through (narrow streets, few straight thoroughfares) have
significantly less crime than those that are more permeable. After closing off residential
streets to through traffic, researchers found that "without the heavy traffic of the past,
internal streets could be `taken back' and used for play by children and other forms of
interaction among neighbors."'9
In a Dayton, Ohio case study, traffic calming reduced
neighborhood crime by 25-50% and encouraged residents to get to know their neighbors
better and become more involved in community activities.80 A survey of residents found
that many knew their neighbors better and were more involved in community activities
after these changes.
It is difficult to measure these benefits, although there are indications that they are highly
valued .$' one indication is the number of people who spend their vacations strolling the
pedestrian --friendly streets of pre -automobile cities, or at pedestrian -oriented resorts such
as Disneyland. Similarly, homes in "neotraditional" neighborhoods command higher prices
in part because buyers expect more neighborhood interaction."
Quantifying These Benefits
Although these benefits appear to be highly valued by many residents, they are difficult to
quantify.
75 Suzanne Crowhurst Lennard and Henry Lenard, Livable Cities Observed, Gondolier (Carmel) 1995.
77 Donald Appleyard, Livable Streets, University of California Press (Berkeley), 198 L
78 Mark Jones and Kenneth Lowrey, "Street Barriers in American Cities," Urban Geography, Vol. 16,
No. 2, 1995, pp - 112W 122.
7
9 Henry Cisneros, Defensible Space, HUD (Wash. DC; www.huduser.or ), 1995.
84 Stephen Burrington & Bennet Heart, City Routes, City bights, Conservation Law Foundation (Boston;
www.clf or ), 1998.
"' James Howard Kunstler, The Geography of Nowhere, Simon & Schuster (New Fork), 1993; Philip
Langdon, A Better Place to Live, HarperPerennial (Neva York), 1994.
82 "Neighborhoods Reborn," Consumer Reports, May 1996, pp. 24-30.
In
Traffic Calming Benefits, Costs and Equity Impacts
6. Increased Property Values
Most homebuyers prefer homes on streets with lower traffic volumes and speeds. For this
reason homes on cul de sac streets command a price premium and new developments are
being built with streets designed to control traffic." Reduced traffic speeds and pedestrian
amenities can also make small commercial districts more attractive and accessible to
nearby residents. one study found that traffic restraints that reduced traffic volumes on
residential streets by several hundred vehicles per day increased house values by an
average of 18%.8-4 other studies find similar results.$.
These higher values partly reflect the safety and environmental benefits experienced by
residents, so it is important to avoid double -counting. Safety and environmental benefits to
non-residents (non-residents walking or cycling along a street, or playing in a nearby park)
are not reflected in residential home prices.
Quantifying This Benefit
Market surveys and consultation with real estate experts can help quantify this benefit in
particular locations. A rough estimate is that each reduction of 100 vehicles per day below
2,000 provides a 1 % increase in adjacent residential property values.16 Traffic speed
reductions also increase adjacent residential property values by reducing noise. A 5-r10
mph reduction can increase adjacent residential property values by about 2%.1' Similar
benefits may occur in commercial areas where traffic calming enhances the street
environment.
7. Reduced Suburban Sprawl
Traffic calming can give residents of existing urban neighborhoods the louver -traffic
amenity often associated with suburban cul-de-sac locations. By creating a more pleasant
urban environment and encouraging the use of non -automotive travel modes, traffic
calming can help reduce "suburban sprawl." Sprawl imposes a number of economic, social
and environmental costs on society."
Quantifying This Benefit
Although reduced sprawl may provide significant benefits in some regions, these benefits
are difficult to quantify.
83 Dan Burden, .Street Design Guidelines for Healthy Neighborhoods, Center for Livable Communities,
Local Government Commission (Sacramento; www.I c.or Icic), 1999.
84 Gordon Bagby, "Effects of Traffic Flow on Residential Property Values," Journal of the American
Planning Association, Vol. 46, No. 1, January 1980, pp. 88-94.
'5 William Hughes and C.F. Sirmans, "Traffic Externalities and Single -Family House Prices," Journal of
Regional Science, Vol. 32, No. 4, 1992, pp. 487-500.
86 Based on Bagby, 1980. More research is needed to better quantify these values.
87 M. Modra, Cost -Benefit Analysis of the application of Traffic Noise Insulation Measures to Existing
Houses, EPA (Melbourne), 1984.
" Robert Burchell, et al., The Costs of Sprawl — Revisited, TCRP Report 39, Transportation Research
Board www.nas.edultrb), 1998.
17
Traffic Calming Benefits, Costs and Equity Impacts
Costs
1. Project Expenses
Project expenses include both capital expenses of implementing traffic calming and any
incremental maintenance costs. Because there are many different traffic calming
techniques, devices and conditions, these costs vary widely. Costs also vary depending on
whether traffic calming projects are implemented alone or in conjunction with other road
construction projects. Traffic calming projects often involve a variety of objectives, such
as community beautification, so a portion of project costs may be charged to other
budgets. Table 10 provides generic cost estimates for typical traffic calming measures. A
variety of sources are used to fund traffic calming projects, including federal and state
89
grants, local general funds, development impact fees, and property assessments.
2. Liability Claims
Current experience indicates that traffic calming projects do not cause significant liability
claims. A 1997 survey found that out of more than 1,500 total lawsuits brought against
traffic engineers in 68 jurisdictions, only 6 involved traffic calming devices, and only two
were successful.9 1 Vehicle damage during construction, and inadequately signed speed
humps appear to be the most common cause of claims. Monetary awards tend to be
relatively small. As designers and motorists become more familiar with traffic calming, and
as specific strategies become widely accepted practices, the risk of claims is likely to
decline. Liability can be minimized by using standard strategies and designs published by
organizations such as ITE or TAC, and by using appropriate signage to warn drivers.
Asha Weinstein and Elizabeth Deakin, "How Local Jurisdictions Finance Traffic Calming Projects,"
Transportation Quarterly, Vol. 53, No. 3, Summer 1999, pp. 75-87.
90 Making Streets that York, City of Seattle (www.ci.seattle.wa.us/npo/tbl.is.htm), 1996.
91 Ransford S. McCourt, Survey of Safety Programs, tTE Traffic Engineering Council
(www.westemite.com/technical/sip,nalsurvo/ntm),. 1997.
18
Traffic Calming Benefits, Costs and Equity Impacts
3. Vehicle Delay
Traffic calming reduces average motor vehicle speeds, and sometimes increases the
distances required to drive to destinations. This increases automobile users' travel time.
On the other hand, traffic calming that reduces excess speeds and smoothes traffic flow
(such as calming an arterial, or replacing a conventional intersection with a roundabout92)
can increase total roadway capacity and reduce congestion delays, since roadway capacity
is maximized at 30-40 mph, and less on typical streets with stoplight intersections.9
Quantifying This Cost
Conventional assessment techniques can be used to value incremental travel time costs.94
For example, a traffic calming project may reduce average traffic speeds from 30 to 20
mph, which adds 30 seconds to an average trip, assuming 0.5 mile per trip is traffic
calmed. Personal travel time is usually valued at 50% of average wage rates. A 30 second
travel time increase is therefore considered worth 50, at $12 per hour average wages. This
represents a maximum cost. Increased travel time that results when vehicle speeds are
reduced to the posted speed limit are not generally considered a "cost." If the posted
speed limit on the route is 25 mph, only half the 30 second increase in travel time would
be considered a cost, the rest is simply compliance with traffic law.
Motorists respond in various ways to reduced traffic speeds. Some trips are rerouted,
consolidated or eliminated entirely, particularly over the long term as transport and land
use patterns achieve a new equilibrium.95 As a result, delay costs decline over time as area
motorists adjust their travel and land use patterns to account for changes in trip speeds.
Eventually (over 5-10 years), a new land use equilibrium ,will develop based on lower
traffic speeds, so no time is lost. This indicates that net travel time costs are 80% in the
short-term, and decline to 0% over the long-term. For example, if 1,000 vehicles per day
currently use a roadway, and a traffic calming project increases average travel time by 1
minute per mile, an estimate of total travel delay ignoring travel elasticities is:
1,000 x I -minute = 16.6 hours per day.
A more accurate estimate that incorporates elasticity values is:
1,000 x 1-minute x (1 + E)
where E is an elasticity value that changes from 4.2 in the short-term, to -1.0 over the
long term. This represents traffic that changes routes, destinations or modes to avoid
delay. Thus, the actual total delay starts at 13:25 and declines over time. A new land use
equilibrium eventually develops based on traffic calmed travel speeds, so no time is lost.
92 George Jacquesrnart, Modern Roundabout .Practice in the United States, NCHRP Synthesis 264 (TRB,
www.nas.edultrb), 1998; Modern Roundabout website www.roundabouts.com).
93 W. Hornburger, et al., Fundamentals of Traffic Engineering, 14'h Edition, Institute of Transportation
Studies (Berkeley), 1996, Chapter 4.
94 William Waters, The Value of Time Savings for The Economic Evaluation of ffighway Investments in
British Columbia, BC Ministry of Transportation and Highways(_www.th.g`ov.bc.calbchighvvays), 1992.
95 Cairns, Hass -Blau and Goodwin, Traffic Impacts of Highway Capacity Deductions: Assessment of the
Evidence, London Transport Planning (London; www.ucl.ac.uk/transportW-studies/scI.htrn), 1998.
19
Traffic Calming Benefits, Costs and Equity Impacts
4. Traffic Spillover onto Other Roads
Traffic calming on one road may cause some vehicle trips to shift to other roads. Net
impacts depend on whether the roads experiencing additional traffic are equally sensitive
as the road with reduced traffic. Shifting traffic from low -volume residential streets to
high -volume arterial roads reduces most external impacts, providing net benefits, although
it may increase arterial traffic congestion.
Spillover traffic may be predicted using traffic models. However, most models tend to
overestimate spillover impacts because they use fixed trip tables (they assume that the
same number of trips will occur between zones regardless of travel conditions). Fixed trip
table traffic models tend to overestimate traffic spillover costs.
Quantifying This Cost
Spillover costs can be calculated by determining the number of vehicle trips shifted to
other streets and calculating the increased cost these trips impose.
5. Problems for Emergency and Service Vehicles
Some traffic calming techniques can cause delay and other problems for fire trucks and
heavy service vehicles (buses, garbage trucks and snowplows). one study found that
speed humps and traffic circles can delay fire trucks up to 10.7 seconds per device,
depending on vehicle type and conditions.96 In one city, traffic calming increased average
97 emergency vehicle response time by two seconds, from 3:23 to 3:25 minutes. This
increase is much smaller than differences in response times between residential areas.9'
Incremental risk to residents from fire truck delays are usually much smaller than increased
road safety from traffic calming accident reductions.
These problems can be minimized if they are considered in project planning. Some street
closures include short-cuts for emergency and service vehicles. Communities may
purchase smaller fire and garbage trucks for use in traffic calmed areas, or develop more
dispersed fire stations. Here are other ways to minimize these problems:
1. Establish extra large no -parking zones adjacent to fire hydrants to help fire trucks maneuver.
2. Limit the use of skinny streets to low- and medium -density residential neighborhoods.-
3. Limit the use of skinny streets to streets which are part of an interconnected network of streets
(i.e., connected on both sides to other public streets, no cul-de-sacs).
4. Avoid skinny streets on primary emergency vehicle routes.
5. Prohibiting parking within 50' of an intersection (to allow fire trucks to make the turn).
96 Crysttal Atkins and Michael Coleman, "Influence of Traffic Calming on Emergency Response Times,"
ITE Journal, August 1997, pp. 42-47; www.trans.ci.portland.or.us/Traffic Managementltrafficcalming.
9' "First Phase of Traffic Calming Project in Sacramento Yields Positive Effects," Urban Transportation
Monitor, Vol. 13, No. 6, April 2, 1999, p. 4.
98 A. Ann Sorensen and J. Dixon Esseks, Living on the Edge; The Costs and Risks of Scatter
Development, American Farmland Trust (Washington DC; httv:Hfarrn.fic.niu.edu/cae/catter/index.htm),
March 1998.
20
Traffic Calming Benefits, Costs and Equity Impacts
6. Driver Frustration
Some drivers may be frustrated if confused by unfamiliar traffic calming devices or
because they want to go faster than traffic calming allows. This is usually a temporary
problem as drivers become familiar with traffic calming and accustomed to the new road
conditions. on the other hand, some drivers may experience reduced stress from lower
traffic speeds.
Quantifying This Cost
This is generally a minor and temporary cost.
6. Problems For Bicyclists And Visually Impaired Pedestrians
Some traffic calming measures can create problems for bicyclists, particularly if they
reduce lane widths, create confusion at intersections, or include bumpy or slippery
surfaces.99 These impacts depend on specific conditions. For example, road narrowing
may be a problem where traffic speeds are relatively fast, but may not be a problem if
vehicle traffic slows so bicyclists can ride comfortably in the traffic flow.
Some traffic calming techniques can cause problems for visually impaired pedestrians,
particularly if they eliminate curbs and edges that blind pedestrians use as references, or if
they create unusual sidewalk or traffic configurations.100 Specific concerns include:
Where crosswalks are raised to curb level and there is no detectable warning (such as textured
pavement), blind pedestrians may have no way to know when they enter the street, and
accidentally walk into traffic."'
Blind pedestrians may be confused when they first encounter street crossings with projected
intersections (neckdowns).
Roundabout intersections may be more difficult for blind pedestrians to because they do not
have straight traffic or regular breaks in traffic flow.
These problems are likely to decline as planners incorporate these concerns into traffic
calming designs, and as cyclists and visually impaired pedestrians become more familiar
with various traffic calming devices.
99 Bicyclists: Caught in the .Middle, PTI, (httv://vti.nw.dc.us/task forcesltrans ortationldocsltrafcalm)
' aQ B.L. Bentzen and J.M. Barlow, "Impact of Curb Ramps on the Safety of Persons Who Are Blind,"
Journal of Visual Impairment and Blindness, Vol. 89, 1995, pp. 319-328.
'°' J.S. Hauger, et al., "Detectable warning Surfaces at Curb Ramps," Journal of Visual Impainnent and
Blindness, Vol. 90, 1996, pp. 512-525.
21
Traffic Calming Benefits, Costs and Equity Impacts
Equity Impacts
Equity is concerned with the fair distribution of costs and benefits.° There are two major
categories of equity. Horizontal equity refers to the distribution of impacts among people
or groups considered to be equal in wealth and ability. Vertical equity refers to the
distribution of impacts between people or groups that differ in wealth and ability, with the
assumption that people who are disadvantaged may require greater public resources.
Horizontal Equity
Motor vehicles, by their nature, impose external costs on non -motorized travel.
Pedestrians and cyclists are far more likely to be killed or injured in a traffic accident than
are vehicle occupants. Motor vehicles also impose pollution externalities. Such impacts are
inequitable, unless they are fully compensated. It could therefore be considered equitable
to charge motorists for the costs of implementing traffic calming projects to reduce such
impacts.
Public expenditures are sometimes evaluated in terms of whether different groups receive
fair value for their tax payments. Many people assume vehicle user fees pay for public
roads, so motor vehicles should have first priority in roadway use. In fact, vehicle user
taxes cover only a small portion of local road costs, which are mostly funded by local
taxes. ' °' As a result, residents, pedestrians and cyclists have a claim equal or greater than
that of motorists to have roads that meet their needs, even based on the narrow criteria of
who funds the facilities.
If motorists, pedestrians, cyclists and residents are all considered to have equal rights to
safety, mobility, comfort and property, traffic calming can increase horizontal equity by
better balancing different uses of a street. Traffic calming can reduce the uncompensated
accident risks and the delays motor vehicles impose on pedestrians and cyclists, give
residents more control over their neighborhood environments, and increases property
values degraded by higher traffic speeds and volumes.
Vertical equity
In most cases, traffic calming increases vertical equity. Traff c calming often increases
vertical equity. People who are economically, physically and socially disadvantaged tend
to drive less than average, walk and bicycle more than average, and live in urban
neighborhoods that are most impacted by through traffic.
102 Todd Litman, Evaluating Transportation Equity, VTPt (wwwxt i.or), 1999.
03 1997 Federal Highway Cost Allocation Study, USDOT (www.ota.fhwa.dot.gov/heas/final); Todd
Litman, Whose Roads?, VTPI (www.vtoi.org), 1998.
22
Traffic Calming Benefits, Costs and Equity Impacts
Public Support
The public must be involved in planning traffic calming projects in order to develop broad
support.104 Community acceptance can be significantly influenced by details such as
aesthetics, neighborhood security, and impacts on parking.
The first few traffic calming projects implemented in a community tend to be the most
controversial. Public support generally increases as residents become more familiar with
traffic calming and its impacts. For example, the cities of Seattle and Portland, which have
implemented many traffic calming projects, now receive hundreds of annual requests for
more projects, far more than can be funded each year.
Some public works departments have a specific process for selecting traffic calming
projects, which may involve developing a neighborhood traffic management plan in
consultation with area residents, or simply a petition signed by a certain portion of
residents on a street to be calmed. The City of Seattle guarantees that a traffic calming
device can later be removed if residents request. Although this has only occurred once out
of more than Soo projects, it gives residents more confidence knowing that they can
change their mind if they don't consider the project beneficial overall.
Evaluating Traffic Calming Projects
A project evaluation should describe each impact, quantify and monetize (measured in
dollar units) impacts where possible, and indicate how impacts are distributed. Although
monetizing impacts can be helpful, it is important to avoid focusing on impacts just
because they are easy to measure. If monetary units are used for benefit/cost analysis, it is
often useful to perform sensitivity analysis (using high and low range estimates) to test
whether conclusions are reliable under different assumptions.
To avoid double counting, the relationships between these impacts should be carefully
considered. If benefits and costs are monetized and totaled for benefit/cost analysis, it may
be necessary to exclude some impacts that are incorporated in other categories. In
particular, increased property values along traffic calmed streets may reflect increased
road safety and enhanced local environmental quality, rather than being a benefit in itself.
If safety, environmental and social impacts are correctly monetized it may be appropriate
to exclude increased property values as a monetized benefit from the benefit total.
Equity analysis requires identifying how benefits and costs are distributed. A policy
decision may be made to give greater weight to impacts on certain groups. For example,
impacts on residents may be given greater weight than impacts on non-residents, or
impacts on disadvantaged groups (disabled, elderly, low income) may be given greater
weight for the sake of vertical equity.
104
Canadian Guide To Traffic Calming, Transportation Association of Canada (Ottawa; www.tac-
atc.ca/t)ropiams/calmincalmin .htm), 1999.
23
Traffic Calming Benef Is, Costs and Equity Impacts
Traffic Calming Evaluation Example
This example illustrates the evaluation of a major traffic calming program in an urban
neighborhood with S, 000 residents living in 2, 000 households.
Road Safety Benefits
Historical data indicates that there are an average of 50 PDo crashes, 10 injury crashes,
and 0.02 fatal crashes (i.e., one fatality every 50 years) on the roads to be traffic calmed.
The state transportation agency values traffic safety improvements at $3,000,000 per
fatality, $50,000 per injury accident, and $2,500 per PDo avoided. The traffic calming
program is predicted to reduce crashes by 40%. The results, summarized in Table 11,
indicate safety benefits are valued at $274,000 per year.
Table 11 Crash Cost Savings From Traffic Calming
Description
Current
Annual
Crashes
40% Annual
Crash Reduction
Cost Per
Crash
Cost
Savings
Fatal
0.02
0.008
$3,o00,000
$243t0oo
Injury
10
4
$50,000
$200,000
-Property Dama e OnIX
50
20
$23,500
$50,000
Total
1
$2 74, 000
Increased Pedestrian and Cyclist Mo h i l i ty
Area households currently generate an average of 1.9 non -motorized trips per day. Traffic
calming is predicted to increase this by 10% or more, to 2.1+ trips per day. At least 1.5
million annual non --motorized trips (2.1 trips per day x 2,000 households x 365 days)
representing 17% of household trips could benefit.
Reduced Automobile Impacts
In this example, half of the additional walking and bicycling trips are assumed to replace
an automobile trip, a reduction of 0.1+ motor vehicle trips per household per day. This
represents at least 73,000 fewer automobile trips. Reduced vehicle use is estimated to
provide net benefits totaling about $146,000 per year, assuming; $2.00 savings per trip.
Local Environmental Benefits
Traffic noise is predicted to decline on 15 residential streets with 750 residences and 10
businesses. Air pollution impacts are considered uncertain and too small to measure.
Increased Neighborhood Interaction and Crime Prevention
A survey of residents indicates that they value opportunities to increase neighborhood
interaction, particularly because it may reduce crime. This impact is not quantified.
24
Traffic Calming Benefits, Costs and Equity Impacts
Property Values
Five residential streets are predicted to have an average of 200 fewer vehicles per day,
resulting in a 2% increase in property values. Another ten streets will have average traffic
speeds reduced by 5 mph, resulting in a I % increase in property values. This benefit totals
$1 million, with an annualized value of about $53,000, as indicated in Table 12.
Table 12 Increased Property Values from Reduced Traffic Volumes and Speeds
Number
Total
Total Property
Increased
Annualized
Im acts
of Streets
Houses'as
Value'
Property Value
Value'
200 Daily
1% increase per
Vehicle Trips
100 vehicles
Reduced
reduced
5
250
$25 million
$5005000
$261r600
1 % increase per
5 mph Speed
5 mph
Reduction
reduction
10
500
$50 million
$50000
$261,600
Totals
15
750
$75 million
$1, 000, 000
$53, 200
Reduced Suburban Sprawl
This project is likely to help reduce suburban sprawl.
Project Expenses.
The project has capital costs of $800,000 and $5,000 annual increased maintenance costs.
Liability Claims
By using standard traffic calming strategies, liability claims are not expected to increase.
Vehicle Delay.
Traffic surveys indicate that the roads being calmed in this project carry 4,600,000 motor
vehicle trips annually. Average speeds are predicted to decline from 25 mph (2:24 minutes
per mile) to 20 mph (3.-00 minutes per mile) for 0.5 miles, adding 18 seconds to an
average trip. This increases travel time by 23,000 hours per year, a cost of $138,000 per
year at $6 per vehicle hour, if motorists do not change routes or destinations. As described
earlier, delays actually tend to decline over time as travel and land use patterns achieve a
new equilibrium. The actual delay cost is estimated to start at $110,000 (80% of
$138,000) when the project is implemented, and decline to zero over a ten-year period.
Traffic Spillover On Other streets
In this example, spillover traffic onto other residential streets is expected to be minimal,
since the program is comprehensive. Traffic increases on arterials are proportionally small
(400-800 additional vehicles per day on roads carrying 20,000 vehicles per day). This may
slightly increase arterial traffic congestion.
10' Assuming 50 homes per street.
1 m Assuming $100,000 average value per home.
107 20 year with a 7% discount rate.
25
Traffic Calming Benefits, Costs and Equity Impacts
Problems For Emergency Vehicles, Service Vehicles And Snow Removal
Traffic calming strategies selected for this project are designed to accommodate service
vehicles. Average fire truck emergency response time is predicted to increase by 2 seconds
in the traffic calmed area. This impact is considered too small to quantify.
Increased Drivers' Effort And Frustration
Some drivers who are unfamiliar with traffic calming devices are expected to be confused,
and drivers who currently exceed the speed limit are expected to be frustrated by the
traffic calming project. These are both considered short-term effects that should soon
disappear.
Problems for Bicyclists and Visually Impaired Pedestrians
Traffic calming devices are designed to minimize problems for cyclists. For example,
chokers used on busier streets incorporate bike lanes. Some bicyclists who are unfamiliar
with traffic calming devices are expected to be confused in the short term. By using
standard traffic calming designs that incorporate textured surfaces where crosswalks enter
the street without a curb, problems for visually impaired pedestrians are avoided.
OAM
Traffic Calming Benefits, Costs and Equity Impacts
Example Summary
Table 13 summarizes costs and benefits associated with the traffic calming project in this
example.
Table 13 Traffic Calming Impacts
Description
Distribution
uantified Values
Berl a its
Reduced traffic accident
Road users (especially
frequency and severity,
pedestrians and cyclists),
particularly for crashes involving
and society, due to
Increased road safety.
Edestrians and cyclists.
reduced accident costs.
$274,000 peryear
Increased comfort and
mobility for non-
Increased comfort and mobility
1.5+ million annual
motorized travel.
for pedestrians and cyclists.
Pedestrians and cyclists.
tri s benefit.
Increased non -motorized travel
Consumers, who enjoy
substitutes for automobile trips,
more travel choices, and
Reduced automobile
reducing congestion, expenses
society, due to various
impacts.
and pollution.
cost savings.
$146,000 per year.
Residents, visitors, and
Reduced noise at 760
Local environmental
Reduced noise and air pollution,
some businesses (such as
residences and
benefits.
and improved aesthetics.
restaurants .
businesses.
Increased
More hospitable streets
neighborhood
encourage street activities and
Many residents
interaction.
community interaction.
Residents.
benefit.
Reduced traffic speed and
Increased property
volumes increase residential
Residents and property
values.
proErty values.
owners.
$53,000 per year.
Improved urban environment
Reduced suburban
encourages urban infill that
Possible benefit to the
sprawl.
reduces sprawl.
Individuals and society.
region.
Costs
Financial costs associated with
Local governments or a
implementing and maintaining
local improvement
$1,000,000, plus
Project expenses.
traffic calmin facilities.
district.
$5,000 per year.
Increased liability claims caused
Liability claims
by traffic calmin .
Municipal governments.
No chap e
Reduced traffic speeds. Motorists
$110,000 the first
either increase their travel time
year, declining to
Vehicle dela .
or reduce travel distance.
Motorists and businesses.
zero after 10 years.
Traffic spillover on
Traffic calming on one street can
Residents and travelers
Considered minimal
other streets.
shift traffic to other streets.
on other streets.
in this case.
Problems for
Delay to fire trucks, and
People needing
emergency and service
problems for buses, garbage
emergency services,
vehicles.
trucks and snow tows.
ublic agencies.
Minimal in this case.
Increased effort required for
Increased drivers'
driving on traffic calmed roads
Considered a minor,
effort and frustration.
and the resulting frustration.
Drivers.
short-term impact.
Problems for bicyclists
some traffic calming strategies
and visually impaired
cause problems to bicyclists or
Bicyclists and visually
Minimal impact due
edestrians.
visually irn aired pedestrians.
impaired pedestrians.
to good design.
27
Traffic Calming Benefits, Costs and Equity Impacts
The figure below illustrates the monetized benefits and costs projected 15 years into the
future. Benefits are illustrated by bars going up and costs are illustrated by bars going
down. A 7% discount rate is used, resulting in declining magnitude of impacts over time.
In this case, the net present value of the monetized impacts are estimated to total more
than $3.5 million, indicating that the traffic calming project is a worthwhile investment.
Figure 4 Illustration of Traffic Calming Benefit/Cost Analysis
$500,000
$a
-$soo,aoo
Years =?
-$1, 000, 000
■ Road Safety
® Reduced Automobile Impacts
■ Increased Property Values
❑ vehicle Delay
■ Project Expenses
This figure illustrates how benefit/cost analysis results can be presented.
Of course, this analysis only incorporates monetized values. Decision makers must use
their judgment to determine whether impacts that are not monetized may be significant
enough to change the results. In this case, the costs that are not monetized (spillover onto
other streets, driver frustration, fire truck delay and problems for cyclists and visually
impaired pedestrians) are minimized through consideration in the design, and are
considered minor compared with other impacts. On the other hand, some benefits that
were not monetized (increased mobility and comfort for walking and cycling, increased
neighborhood interaction, reduced sprawl, and increased equity) appear to be significant
and so may increase the project's net benefits. As a result, the conclusion that the "project
is a worthwhile investment can be considered robust.
28
Traffic Calming Benefits, Costs and Equity Impacts
Conclusions
This paper describes a comprehensive framework for evaluating traffic calming benefits,
costs and equity impacts. Benefits include increased road safety, increased comfort and
mobility for non -motorized travel, reduced motor vehicle travel, reduced noise and air
pollution, increased neighborhood interactions, increased property values, and a more
attractive streetscape. Traffic calming can help create more livable communities, reduce
automobile dependency, and discourage suburban sprawl. Since pedestrian mobility is
essential for transit use, traffic calming supports transit.
Traffic calming costs may include project expenses, motor vehicle delay, traffic spillover
onto other streets, problems for emergency and service vehicles, driver frustration, and
problems for bicyclists and visually impaired pedestrians. Many objections to traffic
calming relate to specific devices or measures rather than to traffic calming in general.
These concerns may be addressed by considering a broader range of options, and careful
selection of specific techniques that are most appropriate to a particular application.
Traffic calming can increase horizontal equity by reducing motor vehicle external impacts,
and by creating a more balanced transportation system that increases travel choices for
disadvantaged people. It can be argued that local residents' interests should take
precedence over the interests of non-resident motor vehicle users, since vehicle users
impose unreciprocated impacts on residents, and because residents pay most of the costs
of local streets through local taxes. Traffic calming can also increase vertical equity, since
the people who benefit most tend to be economically, physically and socially
disadvantaged relative to those who experience the most disbenefits from traffic calming
(high mileage, suburban drivers).
The impacts of each traffic calming project are unique. There are many different traffic
calming devices and measures, and their impacts vary depending on the application. It is
therefore not possible to provide "generic" estimates of traffic calming benefits and costs.
Each project should be evaluated individually. There are various ways. to evaluate benefits
and costs, and provide this information to decision makers. Some traffic calming benefits
and costs can be quantified using accepted economic techniques. others, such as increased
neighborhood interaction, may be significant but difficult to measure with available
information.
Impacts should be described qualitatively, and quantified as much as possible. It is
important to avoid skewing analysis results by focusing too much on some impacts just
because they are most easily quantified. Tables and graphs can be used to indicate the
magnitude and distribution of impacts, and to compare total benefits and costs. It is
important to avoid double counting. Sensitivity analysis can be used to test whether
conclusions are reliable under a range of possible scenarios.
29
Traffic Calming Benefits, Costs and Equity Impacts
Resources
Bicycle Federation www.bikefed.or ) provides pedestrian and bicycle planning resources.
Dan Burden, Street Design Guidelines for Healthy Neighborhoods, Center for Livable
Communities, Local Government Commission (Sacramento; www.lgc.org/cic), 1999.
Dan Burden and Peter Lagerway, Road Diets Free Millions for New Investment, walkable
Communities www.walkable.or ), 1999.
Stephen Burrington & Veronika Thiebach, Take Back Your Streets; How to Protect Communities
from Asphalt and Traffic, Conservation Law Foundation (Boston; www`clf org), 1995.
Congress for the New Urbanism Narrow Streets database(vwww.sonic.net/abcaia/narrow.htm).
David Engwicht, Street Reclaiming; Creating Livable Streets and Vibrant Communities, New
Society Publishers (www newsocie com), 1999.
Reid Ewing, Transportation and Land Use Innovations; When You Can't Build Your Way out of
Congestion, Planners Press (Chicago; www_plannin .com), 1997.
Institute of Transportation Engineers (Washington DC; www.ite.or } publishes several traffic
calming and pedestrian planning documents.
Local Government Commission (www.lgc.org/ciclpubinfo) provides a variety of useful material.
Modern Roundabouts: www.roundabouts.com and www-uftre.ce.ufl.edu/wwwround/md-home.htm.
National Highway Traffic Safety Administration {www.nhtsa.dotov) provides information on
U.S. accidents and safety programs.
National Transportation Week Pedestrian Website(www.ota.fhwa.dot.gov/ntw/bikeped.htm)
provides links to a number of other pedestrian planning websites.
Oregon Bike and Pedestrian Planning (www..odot.state.or.us/techserv/bik.ewalk/obi)plan.htm) is
an example of bicycle and pedestrian planning at its best.
Partnership for a Walkable America(http.Ilnsc.org�walklwkabout.htm) promotes the benefits of
walking and supports efforts to make communities more pedestrian friendly.
Slow Down You're Going Too Fast, PT1(bltp://I)ti..nw.dc.us/task—forces/trans-oortation/pubs.hlMl).
City of Portland (www.trans.ci.portland.or.us/Traffic Mana ementltraff ccalrnin ) provides
excellent information and materials on traffic calming and pedestrian planning.
City of Seattle (www.ci.seattle.wa.us/npo/tblis.htm. has planning and traffic calming resources.
TAC, Canadian Guide To Traffic Calming, Transportation Association of Canada (Ottawa;
www.tac-atc.cal ra rams/calmin calmin .htm), 1999.
UK Dept, Environment, Transport and Regions (www.roads.detr.goy.uk) provides resources for
creating a safer pedestrian environment, and descriptions of traffic management strategies.
The U.S. Federal Highway Administration's pedestrian program (www.ota.fhwa- dot. govlwalk)
provides pedestrian safety information and resources.
Walkable Communities (www.walkable.org) helps create people -oriented environments.
The WSDOT Pedestrian Website (www,wsdot.wl.gov/hlrd/Sub-defaults/Pedestrian-default.htm)
provides extensive reference information and examples of outstanding programs.
30
Traffic Calming Benefits, Costs and Equity Impacts
Here are related reports available from VTPI:
Land Use Impact Costs of Transportation
Pavement Buster's Guide
Quantifying Nonmotorized Transport Benefits for Achieving TDM Objectives
Transportation Cost Analysis,- Techniques, Estimates and Implications
Whose Roads? Deming Bicyclist's and Pedestrian's Right to Use Public Roads
Yin- Win Transportation .management Strategies
Feedback
The Victoria Transport Policy Institute appreciates feedback, particularly
suggestions for improving our products. After you have finished reading this
report please let us know of any:
• Typographical errors or confusing wording.
• Concepts that were not well explained.
Analysis that is inappropriate or incorrect.
Additional information, ideas or references that could be added to improve
the report.
Thank you Very much for your help.
Victoria Transport Policy Institute
Website: www.vtpi.org Email: info@vtpi.org
1250 Rudiin Street, Victoria, BC, V8V 3R7, CANADA
Phone & Fax 250-360-1560
"Efficiency - Equity - Clarity"
31
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Avon Roundabout Modification for Growth Avon
CO
Binghamton Gateway Roundabout Bin hamton
NY
Napa Prefers CalTrans Roundabout Rutherford;
CA
Confusion at Roundabout Has Drivers Going in
Circles Houston ,..TX
CalTrans Promotes Roundabout Option for Safety
`IVoodland CA
Roundabout Planned to Replace Signal at Worst
Intersection Valparaiso IN
Roundabout Design Grand Have N!I
New London keen for roundabouts Concord NH
Main Street Roundabout Keene NH
Concord Roundabout Editorial Concord, NH
Learning Curve for New Roundabouts Columbus
OH
Rhode Island DOT Favors Roundabouts East
Greenwich R I
Manhattan 2-Lane Roundabout Manhattan KS
Council Approves 2 Roundabouts Near NCSU
Ralei h NC
Two Roundabouts on Highway 153 Replace
Interchange Chattanooga, TN
Missoula Drives in Circles Missoula,�MT
More Roundabouts Planned _W_ic_kenburg, AZ
Wal Mart Plan Turns on Roundabout Concord NH
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RoundaboutsUSA
Rural Roundabouts in Black Hawk County
Waterloo, --IA
Caltrans Reviews Agoura Hills Roundabout
Agoura Hills., CA
Cass Avenue Widening Includes Roundabouts
Macomb Coun MI
Several Roundabouts in Bhutan Bhutan
New Roundabouts on Airport Bypass Kaiispel!, MT
New Roundabouts in Racine Racine Wl
Drivers Learning in Greensboro Greensboro NC
Carrefour Giratoire=Roundabout and
Rondpoint= Traffic Circle in French/English
Quebec Canada
Roundabout MythsDLZ,..Ml
Roundabouts and Access Management: Park City,
University of Utah, west Jordan City TRB 2006
Access Management Conference �
Hamlin Roundabout Rochester Hills MI
Hemel Hempstead 5 Mini Roundabouts in 1973
and 1996 Hemelhempstead,UK
Roundabouts Better Than Being Stuck at a Red
Light Grass Valle CA
Two More Roundabouts for Truckee Truckee CA
Roundabout to Preserve Historic Intersection,
Save Charm Pinehurst NC
Roundabouts and Trucks Anchora e AK
First Roundabout in Ottumwa OttumwaIA
Tallahassee, Leon County 2-Lahe Roundabout
Lane Assignment Tallahasse FL
Portsmouth Roundabout to Revitalize Town
Center Portsmouth, VA
Killingworth Town Roundabout Approach
Killingworth, 9T
TxDOT Adds Roundabout Striping to MUTCD
Springfield Opens Oregon's Second 2-Lane
Roundabout S.pringfeld OR
St, George Modifies Existing Interchange
Roundabouts on 1-15 St. Geor a Utah
Live Roundabout Web'Cam Ohio
More Questions .and Answers about Roundabouts
F o rest La kesy M N
Questions and Answers about Roundabouts
Forest Lakes MN
5 off'6 119-7170M A - 1!l PKA
RoundaboutsUSA
Billings Roundabout Videos and Animations
BiliingsMT
Teardrop Roundabout at Interchange Tryon,NC
School Roundabout Opens in Santa Fe Santa Fe,
NM
Southlake Roundabouts Dallas TES
LSU's First Roundabout Reduces Congestion
Baton Rouge, LA
Nampa Opens its First Roundabout Nampa, Idaho
New Bluffton Roundabouts South Carolina
Copley Opens its First Roundabout,CQPI#Y, Ohio
Nantucket Rotary Going Roundabout Nantucket
MA
More roundabouts in Wisconsin Wisconsin
Roundabouts Will be Liked Over Time Forest
Lakes, MN
Roundabout Coming to Springfield, Oregon
S rin f eld Ore on
Art in Roundabouts Juneau Alaska
British have roundabout way of making traffic safe
Arizona
Roundabout Used to Straighten Road Missouri
Roundabouts Working on the Island Brunswick,
GA
Roundabout Working Near Reno Reno, NV
Malfunction Junction to get 2 Roundabouts
Rutland Vermont
Roundabout Art and Financing'Pa son Arizona
Lake Wobegon Roundabouts Minnesota
Columbia's 5 Roundabouts Reduce Accidents
Columbia_, M0
8 Roundabouts in Gig Harbor Tacoma,_ WA
Roundabouts Reduce Traffic Gridlock and Save
Fuel Newswise and IIHS
5 Roundabouts in La Jolla, CA Unique Funding
San Diego Union and Tribune
Roundabout a Potential Fix at 5-Points
Intersection's Wins�/w-aNton-Salem Journal
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