Traffic Impact StudyTraffl"c Impact Study
Ashley Heights Subdivision
Residniial Development
Ntalispefl, Montana
Prepared For:
Hubert Turner
3300 Hwy 2 West
Kalispell, MT 59901
AsLe Heights Subdivision Kalispell, Montana
Table of Contents
A.
Executive Summary.................................................................................... I
B .
Project Description....................................................................
. ................ I
C.
Existing Conditions.....................................................................................
I
Traffic Data Collection...........................................................................
3
Level of Service......................................................................................3
D.
Proposed Development..............................................................................
4
E .
Trip Generation and Assignment................................................................
5
F.
Trip Distribution..........................................................................................
6
G.
Traffic Impacts Outside of the Development ...............................................
S
H.
Percent Entering vehicles.......................................................................... 9
I.
Impact Summary & Recommendations....................................................10
List of Tables
Table 1- 2006 Existing Traffic Level of Service Summary .....................................4
Table 2 -Trip Generation Rates.............................................................................6
Table 3 -Level of Service Summary With the Ashley Heights Subdivision ............ 9
List of Figures
Figure 1— Vicinity Ma............................................................ 9
Figure 2 —Trip Distribution Without U.S. Highway 93 Bypass.................................7
Figure 3 -Trip Distribution With U. S. Highway 93 Bypass ...................................... 7
Ashley Heights Subdivision Kalispell, Montana
Traffic Impact Study
Ashley Heights Subdivision
Kalispell, Montana
A. EXECUTIVE SUMMARY
The Ashley Heights Subdivision will have little effect on the traffic conditions around the proposed
development site. Even if constructed at maximum density (41 units), intersection operations will
remain within acceptable limits and traffic volumes will not exceed the limits of the functional
classifications of any roadways. when the Highway 93 bypass is constructed, Sunnyside Drive
will effectively become a collector route and the functional classification of this roadway should be
changed to match this operating condition. This change in classification will be necessary regardless
of the construction of the Ashley Heights development. No intersection improvements or
modification will be required as part of this development.
B. Project Description
This document studies the possible effect on the surrounding road system from a proposed 8.5-acre
residential development located along Sunnyside Drive in Kalispell, Montana. The document also
identifies any traffic mitigation efforts that the development may require. The project site is located
south of Sunnyside Drive, outside the Kalispell City limits, and would be developed to include up to
41 residential units. See Figure 1 for a location map of the proposed development.
C. EXISTING CONDITIONS
The existing transportation system that would serve this site is a mixture of local, collector, and
minor arterial roadways. These roadways include:
Sunnyside Drive is an east -west local street located directly north of the proposed project site
and will provide direct access for traffic entering and exiting the subdivision. This roadway has
a posted 25 mph speed limit and serves both area residents and other commuters. Sunnyside
Drive is currently functioning as a bypass between the southern portion of Kalispell and F oys
Labe Road. Commuters can use Denver Avenue, Sunnyside Drive, F oys Labe Road, and
Meridian Road to bypass Highway 93 through downtown Kalispell. Sunnyside Drive currently
carries 2,1.00 VPD west of Denver Avenue.
5th Avenue South is a north -south, two-lane roadway classified as a collector roadway south of
l 1 th Street west Street and a minor arterial route north of 11 th Street west. The roadway has a
25 mph speed limit and currently carries 1,600 vPD north of Sunnyside Drive.
Abelin Traffic Services 1 May 2007
As Heights Subdivision KaiLs2ell, Montana
7'h Avenue South is a north -south, two-lane roadway collector roadway that extends north from
Sunnyside Drive to Center Street. The roadway has a 25 mph speed limit.
I I'h Street West is an east -west two-lane minor arterial east of 5 Ih Avenue west and a collector
route west of 5thAvenue. The intersection of I I thStreet West and Main Street is currently
signalized. I
Bismark Street is an cast -west local route that will provide access to the southeast comer of
the proposed project site. This residential roadway currently carries less than 100 VPD.
kLMr
dL
I;r W
16F
Abe lin Traffic Services 2 May 2007
Ashie l ei i s Subdivision aheti, Montana
Traffic Data Collection
ATS obtained turning movement count data collected for the 2007 Kalispell Transportation Plan
from Robert Peccia & Associates. This data was collected in the summer of 2006. ATS also
collected traffic data along Sunnyside Drive and 5th Avenue west in May ?007 in support of this
project. This data is included in Appendix A. of this report. The intersections analyzed for this
project include:
• Foys Lake Road & Vai ley View Road;
• Sunnyside Drive & Denver Avenue;
* 11 th Street west & 71h .Avenue west;
11 1h Street west & 5th Avenue west;
11 1h Street west & I't Avenue West; and
• 1 1 try Street West &Train Street (U.S. Highway 93).
Level of Service
Using the data collected for this project, ATS conducted a Level of Service (LOS) analysis at the
intersections within the area of impact. This evaluation was conducted in accordance with the
procedures outlined in the Transportation Research Board's Highway Capacily Manual (HCA4) -
, pecial .Deport ?09 and the Highway Capacity Software (HCS) version 5.2. Intersections are
graded from A to F representing the average delay that a vehicle entering an intersection can
expect. Typically, a LOS of C or better is considered acceptable for. peak -hour conditions.
Table 1 shows the existing ?006 LOS for the AM and PM peak hours without the traffic: from
the Ashley Heights Subdivision. The LOS calculations are included in Appendix C. The table
indicates that all of the critical intersections in this area are currently functioning adequately. It
is likely that the intersection of I 1 th Street and Main Street will soon fall to LOS D if no
mitigation measures are taken. However, this issue will be resolved when the Highway 93
bypass is constructed and traffic congestion along U.S. Highway 93 should improve
considerably.
Abelin Trgffic Services 3 May 2007
Ashie .lei hts Subdivision Kalispell, Montana
Table 1 - 2006 Existing Traffic Level of Service (LOS) Summary
INTERSECTION
AM Peak Hour
PM Peak Hour
Dela LOS vfc
Delay
LOS We
Fa s Lake Rd. & Valley View
Eastbound Thru/Right
na
na
na
na
na
na
Westbound Left
8.5
A
0.06
7.7
A
0.06
Northbound Left/Right
13.9
B
0.26
12.1
B
0.15
Sunn side Dr. & Denver St.
Eastbound Thru/Right
na
na
na
na
na
na
Westbound Left
7.4
A
0.01
7.5
A
0.05
Northbound Left/Right
3.5
A
0.15
10.3
B
0.13
11 th Street & Avenue
Eastbound Left
7.5
A
0.00
7.6
A
0.00
Westbound Left
7.5
A
0.01
7.4
A
0. o3
Northbound LeftfThru/Right
10.3
B
0.07
10.6
B
0.05
Southbound LeftfThru/Right
11.3
B
0.08
11.8
B
0.14
11 to Street & 5t' Avenue
Eastbound Left
7.5
A
0.01
8.0
A
0.01
Westbound Left
7.6
A
0.01
7.5
A
0.02
Northbound Left/Thru/Right
11.7
B
0.18
11.2
B
0.11
Southbound Left/Th ru/Right
14.1
B
0.18
23.3
C
0.56
11 th Street & 1 "t Avenue
Eastbound LeftfThrufRight
12.5
B
na
17.9
C
na
Westbound LeftJThrufRight
10.0
B
na
13.4
B
net
Northbound LeftfThru/Right
13.8
B
na
21.5
C
na
Southbound LeftfThrufRight
11.0
B
na
17.7
C
na
111h Street & Main Street
29.2
c
33.8
C
Eastbound Lef /ThrufRight
21.3
C
0.50
24.4
C
0.63
Westbound Left/ Th rufR ig ht
18.5
B
0.32
24.2
C
0.55
Northbound Left
18.4
B
0.38
35.7
D
0.55
Northbound Thru/Right
41.7
D
0.96
24.6
C
0.80
Southbound Let
11.9
B
0.05
12.1
B
0.08
Southbound ThrufRight
20.7
C
0.71
48.4
D
0.99
D. PROPOSED DEVELOPMENT
The development currently under consideration for this site includes 8.5 acres of land south of
Sunnyside Drive 0.2 miles merest of Denver Avenue which would be developed into a residential
subdivision. The project site would have a secondary access to the east along Bismark Street.
Depending on the final zoning of the property, the development would have between 26 and 41
Wr
res idert ti al units.
Abelin Traffic Services 4 May 2007
Ashley Heights Subdivision al 1, Montana
The alignment of the U.S. Highway 93 bypass is currently planned to run along the western side of
the proposed development site. The bypass would have full movement grade separated interchanges
at both U.S. Highway 2 and l oys Lake Road. The bypass will also include an off -ramp for
northbound traffic at Sunnyside Drive, but not for southbound traffic and there would be no on -
ramps at Sunnyside Drive. This portion of the bypass is currently scheduled for construction by
ITT in 5-7 years, but is dependant on funding availability.
It should be noted that the construction of a bypass off -ramp onto Sunnyside Drive will effectively
turn Sunnyside Drive in a collector route. It is not typical to have accesses onto or from major
access -controlled highways onto local neighborhood streets. Sunnyside Drive should be
redesignated as a collector or minor arterial route with the construction of the northbound off -ramp
onto Sunnyside Drive.
ATS obtained traffic volume information for Sunnyside Drive from the traffic model produced by
the Montana Department of Transportation for the Kalispell Transportation Plan and analyzed the
data for this report. when analyzing model results, it is important to remember that computer traffic
models are not perfect. while traffic modeling can produce meaningful results, it is still a computer --
generated representation of a human activity and can sometimes compute results that observers
would consider illogical. Traffic models are based on predicted traffic flow patterns and travel
tunes. If two similar adjacent routes are modeled and one of the routes has a computed travel time
one second faster than the ether route, 100% of the traffic will use the faster route. This obviously
would not happen in the real world. if conditions like this are observed, portions of the model must
be altered to reduce this effect.
Traffic models are calibrated to provide accurate traffic volumes on arterial and collector roadways.
Traffic volumes on low -volume local streets can be off considerably. One important example of this
is Sunnyside Drive. The Calibrated traffic model for this road predicts existing traffic volume 60%
to 100% higher than the actual existing traffic volumes. This lager level of calibration on these
streets carries through to future traffic volume predictions. For these reasons, great care must be
taken when analyzing model results.
These traffic modeling results indicate that if no bypass is constructed in this area, then traffic
volumes along Sunnyside Drive will increase by only 10% by 2030. If the full bypass were
constructed, then the traffic model predicts that traffic volumes along Sunnyside .Drive will increase
by 35% by 2030.
E. TRIP GENERATION AND ASSIGNMENT
TS performed a trip generation analysis to determine anticipated future traffic volumes from the
proposed development. ATS used the trip generation rates contained in .'rip Generation (Institute of
Transportation Engineers, Seventh Edition). These rates are the national standard and are based on
Abelin Traffic Services 5 May 2007
Ashley Heights Subdivision Kalispell, Montana
the most current information available to planners. A vehicle `trip" is defined as any trip that either
begins or ends at the development site. Judging from field observations and the typical nature of
residential developments, ATS determined that the critical traffic impacts on the intersections and
roadways would occur during the weekday morning and evening peals hours. This analysis provides
data for each of the three separate possible development density scenarios. At full build -out the
proposed development would produce between 20 and 31 AM peak -hour trips, 26 and 41 PM peak -
hour trips, and 249 to 392 daily trips. The trip generation rates and totals are shown in Table 2.
Table 2 - Trip Generation Rates
AM Peak
Total AM
PM Peak
Total PM
Hour Trip
Peak
Hour Trip
Peak
Weekday
Total
Ends per
Hour Trip
Ends per
Hour Trip
Trip Ends
Weekday
Land Use
Units
Unit
Ends
Unit
Ends
per Unit
Trip Ends
R2-Single Family
20
0.75
20
1.01
20
9.57
249
Residential
R3-Single Family
35
0.75
20
1.01
35
9.57
335
Residential
R4-Single Family
41
0.75
31
1.01
41
9.57
392
Residential
F. TRIP DISTRIBUTION
The traffic distribution and assignment for the proposed subdivision was based upon the existing
ADT volumes along the adjacent roadways and the peak -hour turning volumes. Prior to the
construction of the U.S. Highway 93 bypass, traffic is expected to distribute 40% to/from the west
on Sunnyside Drive to Foys Lake Road, 50% to/from the east on Sunnyside Drive to 1 11h Street
West,, and 10% to/from the south on Denver Avenue. After the Highway 93 bypass is constructed
the trip distribution patterns will change substantially. It is estimated that 10% of the traffic will still
distribute to/from the south on Denver Avenue, but the only other exit from the site will be along
Sunnyside Drive to 11 th Avenue which will need to accommodate 90% of the exiting Traffic. 1t is
likely that 10% of the traffic will be able to enter the site from the south from the bypass exit ramp,
but the remaining 80% of traffic will need to approach from the east on Sunnyside ',Drive. The trip
distribution for these two scenarios is shown graphically in Figure 2 & 3.
Abelin Traffic Services 6 May 2007
Ashly Hei hts Subdivision Kalispell, Montana
40%
0%
Figure 2 —Trip Distributions Without U.S. Highway 93 Bypass
�
Proposed
C
Development
Site
10%
Sunnyside Drive
50%
Figure 3 —Trip Distributions With the U.S. Highway 93 Bypass
Proposed
Development
site
Q
C
a
10%
Sunnyside Drive
90%
Abelin Traffic Services 7 May 2007
AshlfE He hts Subdivision Kalispell, Montana
G. TRAFFIC IMPACTS OUTSIDE of THE DEVELOPMENT
Using the trip generation and trip distribution numbers, ATS determined the future Level of Service
(LOS) for the intersections within the area of impact. This analysis assumed full build -out of the
property at maximum density (41 units). The anticipated LOS at these intersections for full build -
out conditions with the proposed development is shown in Table 3. These calculations are based on
the projected model volumes included in Appendix B of this report.
Table 3 - Level of Service Summary
With The. Ashley Heights Subdivision
AM Peak Hour PM Peak Hour
INTERSECTION Dela LOS sic Delav Los ►plc
Fo s Lake Rd. & Valley View
Eastbound ThrulRight na
na
na na
na
na
Westbound Left 8.5
A
0.06 7.7
A
0. 07
Northbound Left/Right 14.3
B
0.28 12.2
B
0.16
Sunn side Dr. & Denver St.
Eastbound ThrulRight na
na
na na
na
na
Westbound Left 7.4
A
0.01 7.6
A
0.05
Northbound Left/Right 9.6
A
0.16 10.6
B
0.14
11 th Street & 7th Avenue
Eastbound Left 7.5
A
0.00 7.6
A
0.00
Westbound Left 7.5
A
0.01 7.4
A
0.03
Northbound Left/ThrulRight 10.4
B
0.08 10.6
B
0.05
Southbound LeftlTh ru/Right '# 1.4
B
0.08 11.9
B
0.15
11 th Street & 6th Avenue
Eastbound Left 7.6
A
0.01 8.0
A
0.01
Westbound Left 7.6
A
0.01 7.5
A
0.02
Northbound LeftlThrulRight 11.8
B
0.20 11.2
B
0.11
Southbound LeftlThrulRight 14.5
B
0.18 23.3
C
0.56
11 th Street & 1' Avenue
Eastbound LeftlThrulRight 12.7
B
na 18.3
C
na
Westbound LeftlThru/Right 10.1
B
na 13.6
B
na
Northbound LeftlThrulRight 13.8
B
na 22.1
C
na
Southbound Left/Thru/Right 11.1
B
na 18..1
C
na
11 u" Street & Main Street 29.2
O
34.0
C
Eastbound Left/Th rulRig ht 1. 5
C
0.51 24.5
C
0.63
Westbound LeftlThrufRight 18.6
B
0.32 24.4
C
0.57
Northbound Left 18.4
B
0.38 35.7
D
0.55
Northbound ThrulRight 41.7
D
0.96 24.6
C
0.80
Southbound Left 11.9
B
0.05 12.1
B
0.08
Southbound ThrulRight 20.7
C
0.71 48.6
D
0.99
Abelin Traffic Services 8 May 2007
Ashley I-ieiots Subdivision Kalispell, Montana
Table 3 indicates that all of the intersections within this area will continue to operate at acceptable
levels of service thought the construction of the Ashley Heights Subdivision. No intersection
mitigation measures would be required as part of this project.
The proposed development will increase traffic volumes along area roadways. Traffic volumes
along Sunnyside Drive will increase by Zoo VPD bath east and west of the development site.
Traffic volumes on 51h Avenue 'west will also increase by approximately Zoo VPD. However, total
traffic volumes along Sunnyside Drive will not exceed 3,000 VPD and traffic volumes along 5th
.Avenue west will not exceed 2,000 VPD. These volumes are within the limits of each of these
roadways based on their existing functional classifications. As a general rule traffic volumes on
local streets (Sunnyside Drive) should not exceed 3,000 and traffic volumes on collector routes (51h
Avenue west) should not exceed 10,000 VPD. The traffic volume increase along Bismark Street
would be minimal.
When the Highway 93 bypass is ultimately constructed, the traffic patterns in this area will likely
change substantially. The total traffic on Sunnyside Drive will likely increase due to the direct
connection with the bypass (as described in section D) and Sunnyside Drive will effectively become
a collector route through this area. The traffic volumes on area roadways will remain at half of the
recommended limits for collector routes (3,500-4,500 VPD). It is possible that the construction of
the bypass will force more traffic onto 7th Avenue west, however this roadway is also a designated
collector route and traffic volumes along the roadway should remain relatively tow (less than 2,000)
VPD which is well within the limit of even a lower classification local street.
H. PERCENT ENTERING VEHICLES
.ITS calculated the percent of the entering volume that would be directly attributed to the proposed
development at downstream intersections at full build -out. The percent increase in entering volumes
gives a good indication of how a development will affect a roadway or intersection. The study
indicates that the development will increase the traffic volumes at area intersections between 1 % and
10% under the highest density development scenario. The increase in traffic volumes at each
intersection is shown in Table 4.
Table 4 — Percent Traffic Volume Increases
Intersection
Percent Volume
Increase
Fe
Labe Road & Valley View Road
3%
Sunn side Drive & Denver Avenue
10%
11
Street Iffiest & 7Avenue Vest
1 %
11
Street West & 5 Avenue West
3%
11
Street West & 1 s Ave n ue West
1 %
1=1 h
Street best & Main Street
0.3%
Abelin Traffic Services 9 May 2007
Ashley Hei hts Subdivision Kalis eitd Montana
f. IMPACT SUMMARY & RECOMMENDATIONS
The Ashley Heights Subdivision will have little effect on the traffic conditions around the proposed
development site. Even if constructed at maximum density (41 units), intersection operations will
remain within acceptable limits and traffic volumes will. not exceed the limits of the functional
classifications of any roadways. when the Highway 93 bypass is constructed, Sunnyside Drive
will effectively become a collector route and the functional classification of this roadway should be
changed to match this operating condition. This change in classification will be necessary regardless
of the construction of the Ashley Heights development. No intersection improvements or
modification will be required as part of this development.
A.belin Traffic Services 10 May 2007