HomeMy WebLinkAboutBB_Traffic Impact Study
Traffic Impact Study
East Main Street Development
Bozeman, Montana
July 2016
East Main Street Development Traffic Impact Study
TABLE OF CONTENTS
Executive Summary ...................................................................................................... 1
Introduction ............................................................................................................... 2
Study Area ............................................................................................................. 2
Study Intersections ................................................................................................ 2
Methodology ........................................................................................................... 4
Data Collection ..................................................................................................... 4
Trip Generation .................................................................................................... 4
Trip Distribution and Assignment ............................................................................... 4
Capacity Analysis .................................................................................................. 4
Signal Warrant Analysis ........................................................................................... 5
Turn Lane Warrant Analysis ...................................................................................... 5
Access Spacing Analysis ........................................................................................... 5
Existing Conditions ....................................................................................................... 6
Bicycle and Pedestrian Facilities .................................................................................. 7
Signal Warrant Analysis .............................................................................................. 7
Intersection Capacity Analysis Results ............................................................................ 8
2016 Development Scenario ............................................................................................ 9
Trip Generation ....................................................................................................... 9
Trip Distribution and Assignment ................................................................................. 10
Signal Warrant Analysis ............................................................................................. 16
Intersection Capacity Analysis Results ........................................................................... 22
Access Spacing Analysis ............................................................................................ 25
Other Access Spacing Considerations ............................................................................ 25
Queuing Analysis ..................................................................................................... 25
Bicycle and Pedestrian Facilities ................................................................................. 28
Recommendations ..................................................................................................... 29
East Main Street Development Traffic Impact Study
TABLE OF CONTENTS
Table of Figures
Figure 1 - Study Area ................................................................................................... 2
Figure 2 - Preliminary Site Plan ....................................................................................... 3
Figure 3 - Study Methodology ......................................................................................... 4
Figure 4 - Existing Traffic Conditions ................................................................................ 6
Figure 5 - Existing Traffic Volumes ................................................................................... 7
Figure 6 - Alternative 1 Trip Assignment ........................................................................... 11
Figure 7 - Alternative 2 Trip Assignment ........................................................................... 12
Figure 8 - Alternative 3 Trip Assignment ........................................................................... 13
Figure 9 - Alternative 4 Trip Assignment ........................................................................... 14
Figure 10 - Alternative 5 Trip Assignment .......................................................................... 15
Figure 11 - Alternative 1: 2016 Development Traffic Volumes................................................. 17
Figure 12 - Alternative 2: 2016 Development Traffic Volumes................................................. 18
Figure 13 - Alternative 3: 2016 Development Traffic Volumes................................................. 19
Figure 14 - Alternative 4: 2016 Development Traffic Volumes................................................. 20
Figure 15 - Alternative 5: 2016 Development Traffic Volumes................................................. 21
Figure 16 – Alt 1 & Alt 2 Anticipated Queuing ..................................................................... 26
Figure 17 - Alt 3 & Alt 4 Anticipated Queuing ..................................................................... 27
Figure 18 - Alt 5 Anticipated Queuing .............................................................................. 28
Table of Tables
Table 1 - Highway Capacity Manual Level of Service Thresholds ................................................ 5
Table 2 - Bozeman City Code Access Spacing Requirements ..................................................... 5
Table 3 - Existing Intersection Capacity Analysis Results ......................................................... 8
Table 5 - Development Trip Generation Summary ................................................................. 9
Table 4 - Development Trips by Land Use Category ............................................................... 9
Table 6 - Development Trip Origin/Distribution Summary ...................................................... 10
Table 7 - 2016 Development Scenario Intersection Capacity Analysis Results ............................... 22
Table 8 – Alternatives’ Benefit & Weakness Summary ........................................................... 24
Appendix
Appendix A – Turning Movement Counts
Appendix B – Capacity Analysis Worksheets
Appendix C – Signal Warrant Analysis
Appendix D – Queuing Summary
East Main Street Development Traffic Impact Study 1
EXECUTIVE SUMMARY
This traffic study was completed for the proposed East Main Street development in Bozeman, Montana.
Two traffic scenarios were evaluated for the proposed development. These scenarios include: Existing
Conditions and 2016 Development Conditions. The following recommendations for the study roadways
are based upon the results of the analyses completed for each scenario.
Signalization of the Haggerty Lane and East Main Street intersection is recommended as it would
reduce delay and improve LOS under both existing and development conditions. Signalization would
greatly improve the northbound approach from LOS “E” under existing PM peak hour stop-controlled
conditions to LOS “B” under development PM peak signalized conditions. Alternatives analysis assumes
the Haggerty Lane and East Main Street intersection is signalized. If this intersection was left
unsignalized, it would result in higher delays and operate at LOS “F”.
Analyses were performed for the following site access alternatives:
Alternative 1: Full accesses off of Highland Boulevard, East Main Street and Haggerty Lane
Alternative 2: Full accesses off of Highland Boulevard and Haggerty Lane (no development
access on East Main Street)
Alternative 3: Restricted access right-in and right-out (RIRO) off of Highland Boulevard, Full
accesses off East Main Street and Haggerty Lane
Alternative 4: Restricted access RIRO off of Highland Boulevard and East Main Street, Full
access off of Haggerty Lane
Alternative 5: Restricted access off Highland Boulevard right-in and right and left-out (RIRLO)
and East Main Street left and right-in and right out (LRIRO), Full access off of Haggerty Lane
Based on the analysis conducted on five alternatives for access to the development, it is recommended
that further discussions with the city of Bozeman and MDT be undertaken to determine the desired
access alternative for implementation. It is recommended that three alternatives be further discussed:
Alternative 1: Alternative 1 is preferred by the developer and would be the easiest to implement. It
does create issues with LOS at multiple locations and falls furthest from meeting Bozeman city code for
access spacing. However, it is the only alternative that would not have potential impacts to other
private establishments’ access across the road along both Highland Boulevard and East Main Street.
Alternative 4: Alternative 4 provides the best traffic operations for all adjacent roadways and comes
closest to meeting Bozeman city code for access spacing. However, access to the development from
the east is limited to Haggerty Lane, and traffic leaving the development to travel south on Highland
Boulevard must use the Haggerty Lane exit or find another route/U-turn to access Highland Boulevard.
Alternative 5: Alternative 5 provides good traffic operations for all adjacent roadways and provides
slightly less access restrictions than Alternative 4. Access to and from the development is superior to
Alternative 4 as traffic to and from all directions has good options for entering and leaving the site.
It is recommended that Alternative 2 and Alternative 3 be eliminated from further consideration due to
LOS impacts and minimal benefits in comparison to the other alternatives.
The proposed site plan shows how sidewalks are proposed to connect to building and parking areas
within the development. The site plan also shows sidewalks proposed along Highland Boulevard, East
Main Street and Haggerty Lane which may connect to existing and future sidewalk facilities off-site. It
is recommended that sidewalks be installed as is shown in the proposed site plan. Concerns have been
voiced by local citizens regarding safety for pedestrians and bicyclists crossing Highland Boulevard. It
is recommended that these crossings continue to be promoted at the East Main Street traffic signal and
at the crossing located south of East Curtiss Street.
East Main Street Development Traffic Impact Study 2
INTRODUCTION
The purpose of this study is to identify traffic operations or safety issues that could be triggered by the
addition of traffic related to the proposed East Main Street development in Bozeman, Montana. This
report has been developed to provide technically sound mitigation options to development-related
issues identified during the analysis process. This traffic impact study assumes the proposed
development will be constructed in 2016.
Study Area
This study was completed for the traffic impacts corresponding to the proposed development. Initial
plans indicate three new buildings on the site including a grocery store, retail shops, office spaces, and
residential spaces. The proposed development site is located on the south side of East Main Street,
between Highland Boulevard and Haggerty Lane in Bozeman, Montana. The surrounding land is of
mixed usage with businesses along the north side of East Main Street, a residential neighborhood to the
west, and a softball field complex to the south. The proposed development location and latest site
plan can be seen in Figure 1 and Figure 2 respectively.
East Main Street is classified as a principal arterial, Highland Boulevard is classified as a minor arterial
and Haggerty Lane is classified as a major collector. Under current conditions, East Main Street has a
posted speed limit of 40 MPH, Highland Boulevard and Haggerty Lane have a 35 MPH posted speed limit
and all other roadways within the study area operate under a 25 MPH speed limit.
Study Intersections
The following intersections were evaluated within this study (see Figure 1):
1. Highland Boulevard and East Main Street – Currently signalized
2. Highland Boulevard and East Curtiss Street – Currently two-way stop controlled on East Curtiss Street
3. Haggerty Lane and East Main Street – Currently two-way stop controlled on Haggerty Lane
4. Cypress Street and East Main Street – Currently two-way stop controlled on Cypress Street
Figure 1 - Study Area
East Main Street Development Traffic Impact Study 3
Figure 2 - Preliminary Site Plan
East Main Street Development Traffic Impact Study 4
Methodology
Within this study, the following traffic
conditions were analyzed to evaluate traffic
impacts of the proposed development:
2016 Existing Conditions – Existing Conditions
based on field collected data prior to proposed
development
2016 Conditions with Development Traffic –
Traffic Conditions expected with construction of
proposed development
Mitigation Strategies – Possible improvements
identified to mitigate development-related
deficiencies
Figure 3, to the right, illustrates the planning
process used within this study.
Data Collection
Weekday AM and PM peak hour turning movements collected at study intersections in October 2015
were provide with the exception of Highland Boulevard and East Curtiss Street with was collected by
KLJ in May 2016. Average daily traffic volumes (ADT) within the study area were obtained from the
Montana Department of Transportation (MDT).
Trip Generation
Site-generated volumes were estimated using the Institute of Transportation Engineers’ Trip
Generation Manual.
Trip Distribution and Assignment
Trip distribution refers to the origin for entering trips and the destination for exiting trips to and from
the proposed site. Trip assignment is the designated routing of trips between origin and destination.
Both origins and destination for trips generated by the proposed site were estimated based on average
daily traffic volumes obtained from MDT. Trips were assigned to the existing road network based upon
engineering judgement, estimating the most ideal and reasonable route between origins and
destination.
Capacity Analysis
Capacity analyses were performed using the Synchro 9 software, which implements an analysis
methodology based on that in the Highway Capacity Manual to determine intersection delay and level
of service. Level of service (LOS) is the qualitative measure of operational performance of
transportation infrastructure using grades ranging from “A” to “F”, with “A” being the optimal level of
service and “F” indicating breakdown of traffic flow. A breakdown of the HCM grading scale can be
seen in Table 1.
•Data Collection
•Capacity Analysis
•Signal Warrant Alanysis
2016 Existing Conditions
•Trip Generation, Distribution, and Assignment
•Capacity Analysis
•Signal Warrant Analysis
•Access Spacing Analysis
2016 Conditions with Development Traffic
Mitigaion Strategies
Figure 3 - Study Methodology
East Main Street Development Traffic Impact Study 5
For intersection analyses within this study, intersection operations at LOS “C” or better are to be
considered to be acceptable.
Table 1 - Highway Capacity Manual Level of Service Thresholds
Signal Warrant Analysis
At all unsignalized study intersections, KLJ performed signal warrant analyses in accordance with
guidelines in the 2009 Manual on Traffic Control Devices.
Turn Lane Warrant Analysis
MDT turn lane warrants were analyzed at all study intersections. Turn lanes will be considered based
on the results of operational analyses.
Access Spacing Analysis
The minimum access spacing found in the Bozeman City Code can be seen in Table 2. For the purposes
of this study, queues from the capacity analysis will be used to determine whether there will be
potential issues with proposed access spacing. Access spacing analyses were performed for
development accesses off Highland Boulevard, East Main Street and Haggerty Lane.
Table 2 - Bozeman City Code Access Spacing Requirements
Access Located on
Arterial Streets
Access Located on
Collector Streets
Average Spacing In All Districts In All Districts
Partial Access1 315' 150'
Full Access2 660' 330'
Minimum Seperation 315' 150'
1: Partial access includes right turn in and out only
2: Full access allows all turn movements, in and out
Signalized Unsignalized
≤ 10 ≤ 10 A F
> 10-20 > 10-15 B F
> 20-35 > 15-25 C F
> 35-55 > 25-35 D F
> 55-80 > 35-50 E F
> 80 > 50 F F
Control Delay (sec/veh)Volume
<
Capacity
Volume
>
Capacity
East Main Street Development Traffic Impact Study 6
EXISTING CONDITIONS
Analyses performed for the existing transportation network traffic scenario include the identification of
existing roadway/traffic characteristics, signal warrant analysis, and turn lane warrant analysis.
Existing daily traffic volumes can be seen in Figure 4. Intersection geometries and peak hour traffic
volumes can be seen in Figure 5.
Figure 4 - Existing Traffic Conditions
East Main Street Development Traffic Impact Study 7
Figure 5 - Existing Traffic Volumes
Bicycle and Pedestrian Facilities
On-street bicycle facilities are located on both sides of the East Main Street and Haggerty Lane
roadways. Sidewalks running along East Main Street conclude at Highland Boulevard on the southern
side and between Highland Boulevard and Haggerty Lane on the northern side. A shared-use path runs
along the western side of Highland Boulevard
Signal Warrant Analysis
Unsignalized intersections within the study area were analyzed to determine if installation of traffic
signalization would be warranted per guidelines published in the Manual on Uniform Traffic Control
Devices (MUTCD). The eight-hour warrant, four-hour warrant, and peak hour warrants were analyzed
for this study.
The four-hour volume warrant and peak hour volume warrant were met at the intersection of Haggerty
Lane and East Main Street under existing traffic conditions. All other unsignalized study intersections
do not meet signal warrants under background traffic conditions. Signal warrant analysis results are
found in Appendix C.
East Main Street Development Traffic Impact Study 8
Intersection Capacity Analysis Results
Intersection capacity analyses were performed for existing weekday AM peak hour and PM peak hour
traffic conditions at all study intersections. Intersection capacity analysis spreadsheets are found in
Appendix B. All study intersections with the exception of the Haggerty Lane and East Main Street
intersection were found to currently have acceptable operations, per MDT standards. (See Table 3)
The Haggerty Lane and East Main Street intersection currently operates at an overall LOS “A” during
the AM and PM peak hours. However, deficiencies are experienced with LOS “E” reached for the PM
peak hour on the northbound approach.
Table 3 - Existing Intersection Capacity Analysis Results
Overall EB WB NB SB
B BBBB
13.4 13.5 14.2 10.9 13.1
B CBBA
17.0 23.6 14.8 11.7 8.8
A AAAA
1.1 6.33.40.90.9
A AAAA
1.2 7.89.40.90.9
A AABA
1.5 0.4 1.8 12.4 2.3
A AABB
1.5 0.8 2.0 10.4 13.4
A AABB
2.7 2.1 1.8 12.3 10.0
A AAE C
7.1 3.5 1.8 42.3 24.4
East Main Street
&
Haggerty Lane
Existing
NB/SB
Stop
Control
AM Peak
PM Peak
Highland Boulevard
&
East Curtiss Street
Existing
EB/WB
Stop
Control
AM Peak
PM Peak
East Main Street
&
Cypress Street
Existing
NB/SB
Stop
Control
AM Peak
PM Peak
Intersection Lane
Geometry
Traffic
Control
Time
Period
Level of Service / Delay (seconds)
East Main Street
&
Highland Boulevard
Existing Signalized
AM Peak
PM Peak
East Main Street Development Traffic Impact Study 9
2016 DEVELOPMENT SCENARIO
The 2016 development scenario analyses were performed for conditions with site generated traffic
added to the existing transportation network traffic. Analyses performed for this scenario include trip
generation, distribution, and assignment, signal warrant analysis, turn lane warrant analysis, and
access spacing analysis. These analyses were performed for the following site access alternatives:
Alternative 1: Full accesses off of Highland Boulevard, East Main Street and Haggerty Lane
Alternative 2: Full accesses off of Highland Boulevard and Haggerty Lane (no development
access on East Main Street)
Alternative 3: Restricted access right-in and right-out (RIRO) off of Highland Boulevard, Full
accesses off East Main Street and Haggerty Lane
Alternative 4: Restricted access RIRO off of Highland Boulevard and East Main Street, Full
access off of Haggerty Lane
Alternative 5: Restricted access off Highland Boulevard right-in and right and left-out (RIRLO)
and East Main Street left and right-in and right out (LRIRO), Full access off of Haggerty Lane
The intersection of Haggerty Lane and East Main Street was analyzed as a signalized intersection for
each site access alternative as it was found to meet signalization warrants under existing peak hour
conditions.
Trip Generation
Site generated traffic was estimated using the Institute of Transportation Engineers’ (ITE) Trip
Generation Manual. Applying the applicable ITE land use categories, daily, AM and PM Peak hour trips
were calculated for the proposed development as seen in Table 4 and Table 5.
Table 4 - Development Trip Generation Summary
Square
Footage
Independent
Variable
Trip
Generation
Rate
AM Peak Hr
Trips
(avg.)
Trip
Generation
Rate
PM Peak Hr
Trips
(avg.)
Trip
Generation
Rate
Weekday
Trips
(avg.)
Trip
Generation
Rate
Weekday
Trips
(min.)
33000 1000 sf 1.56 51 1.49 49 11.03 364 3.58 118
10800 1000 sf 10.81 117 9.85 106 127.15 1373 73.51 794
12 units 0.46 6 0.58 7 6.59 79 5.10 0
3000 1000 sf 2.39 7 3.57 11 36.13 108 23.16 69
12404 1000 sf 1.80 22 1.74 22 11.65 145 5.33 66
17000 1000 sf 0 2.71 46 44.32 753 21.30 362
23736 1000 sf 3.41 81 9.48 225 102.24 2427 68.65 1629
2991 1000 sf 0.30 1 0.32 1 3.56 11 1.51 5
102943 285 467 5260 3044
General Office Building
High-Turnover (Sit-Down) Restaurant
Low Rise Apartment
Land Use Category
Development Totals by Land Use Category
Medical -Dental Office Building
Single Tenant Office Building
Specialty Retail Center
Supermarket
Warehousing
Entering Leaving Entering Leaving Entering Leaving
General Office Building 45 6 8 41 182 182
High‐Turnover (Sit‐Down) Restaurant 64 53 64 43 687 687
Low Rise Apartment 1 4 5 2 40 40
Medical ‐Dental Office Building 6 2 4 7 54 54
Single Tenant Office Building 20 2 3 18 72 72
Specialty Retail Center 0 0 26 20 332 422
Supermarket 50 31 115 110 1213 1213
Warehousing 1 0 0 1 5 5
Total 187 98 224 242 2585 2675
Land Use Type
Trips
AM PM Weekday
Table 5 - Development Trips by Land Use Category
East Main Street Development Traffic Impact Study 10
Trip Distribution and Assignment
Trip distribution refers to the origin for entering trips and the destination for exiting trips to and from
the proposed site. The origins and destinations for site generated traffic were estimated based on
existing average daily traffic on functionally classified roadways in the study area. Estimated site
generated trip distribution can be seen in Table 6.
Table 6 - Development Trip Origin/Distribution Summary
Trip assignment is the designated routing of trips between origin and destination. Trips were assigned
to the existing road network based on engineering judgement, estimating the most ideal and
reasonable route between origins and destination. It is assumed that most traffic to and from the
proposed development site will use major roadways and avoid unclassified roadways, as roads provide
the most direct route to the site. The assumptions seen in Figure 6, Figure 7, Figure 8, Figure 9, and
Figure 10 were applied in order to estimate trip assignments within the study area.
Entering Exiting Entering Exiting
E Main St (W of Site) 12680 40.1% 75 39 90 97
E Main St (E of Site) 7440 23.6% 44 23 53 57
Highland Blvd 8640 27.4% 51 27 61 66
Haggerty Ln 2830 9.0% 17 9 20 22
31590
Trip Origin/Destination %
Origin/Destination
ADT
AM PM
East Main Street Development Traffic Impact Study 11
Alternative 1 - Full accesses off of Highland Boulevard, East Main Street and Haggerty Lane
Origin/Destination E Main St West of Proposed Site- 40.1% of site generated trips
o Route: E Main St to Highland Blvd Access (50% of trips from this origin/destination)
o Route: E Main St to E Main St Access (50% of trips from this origin/destination)
Origin/Destination E Main St East of Proposed Site – 23.6% of site generated trips
o Route: E Main St to Haggerty Ln Access (50% of trips from this origin/destination)
o Route: E Main St to E Main St Access (50% of trips from this origin/destination)
Origin/Destination Highland Blvd – 27.4% of site generated trips
o Route: Highland Blvd to Highland Blvd Access (100% of trips from this
origin/destination)
Origin/Destination Haggerty Ln – 9.0% of site generated trips
o Route: Haggerty Ln to Haggerty Ln Access (100% of trips from this origin/destination)
Figure 6 - Alternative 1 Trip Assignment
East Main Street Development Traffic Impact Study 12
Alternative 2 - Full accesses off of Highland Boulevard and Haggerty Lane (no development access
on East Main Street)
Origin/Destination E Main St West of Proposed Site- 40.1% of site generated trips
o Route: E Main St to Highland Blvd Access (100% of trips from this origin/destination)
Origin/Destination E Main St East of Proposed Site – 23.6% of site generated trips
o Route: E Main St to Haggerty Ln Access (100% of trips from this origin/destination)
Origin/Destination Highland Blvd – 27.4% of site generated trips
o Route: Highland Blvd to Highland Blvd Access (100% of trips from this
origin/destination)
Origin/Destination Haggerty Ln – 9.0% of site generated trips
o Route: Haggerty Ln to Haggerty Ln Access (100% of trips from this origin/destination)
Figure 7 - Alternative 2 Trip Assignment
East Main Street Development Traffic Impact Study 13
Alternative 3 - Restricted access (RIRO) off of Highland Boulevard, Full accesses off East Main
Street and Haggerty Lane
Origin/Destination E Main St West of Proposed Site- 40.1% of site generated trips
o Route: E Main St to Highland Blvd Access (50% of entering trips from this
origin/destination)
o Route: E Main St to E Main St Access (50% of entering trips and 100% of exiting trips
from this origin/destination)
Origin/Destination E Main St East of Proposed Site – 23.6% of site generated trips
o Route: E Main St to Haggerty Ln Access (50% of trips from this origin/destination)
o Route: E Main St to E Main St Access (50% of trips from this origin/destination)
Origin/Destination Highland Blvd – 27.4% of site generated trips
o Route: Highland Blvd to Highland Blvd Access (100% of entering trips from this
origin/destination)
o Route: Highland Blvd to East Main Street Access (50% of exiting trips from this
origin/destination)
o Route: Highland Blvd to Haggerty Lane Access (50% of exiting trips from this
origin/destination)
Origin/Destination Haggerty Ln – 9.0% of site generated trips
o Route: Haggerty Ln to Haggerty Ln Access (100% of trips from this origin/destination)
Figure 8 - Alternative 3 Trip Assignment
East Main Street Development Traffic Impact Study 14
Alternative 4 - Restricted access (RIRO) off of Highland Boulevard and East Main Street, Full access
off of Haggerty Lane
Origin/Destination E Main St West of Proposed Site- 40.1% of site generated trips
o Route: E Main St to Highland Blvd Access (100% of exiting trips from this
origin/destination)
o Route: E Main St to E Main St Access (100% of entering trips from this
origin/destination)
Origin/Destination E Main St East of Proposed Site – 23.6% of site generated trips
o Route: E Main St to Haggerty Ln Access (100% of entering trips from this
origin/destination, 50% of exiting trips from this origin/destination)
o Route: E Main St to E Main St Access (50% of exiting trips from this origin/destination)
Origin/Destination Highland Blvd – 27.4% of site generated trips
o Route: Highland Blvd to Highland Blvd Access (100% of entering trips from this
origin/destination)
o Route: Highland Blvd to Haggerty Lane Access (100% of exiting trips from this
origin/destination)
Origin/Destination Haggerty Ln – 9.0% of site generated trips
o Route: Haggerty Ln to Haggerty Ln Access (100% of trips from this origin/destination)
Figure 9 - Alternative 4 Trip Assignment
East Main Street Development Traffic Impact Study 15
Alternative 5 - Restricted access off of Highland Boulevard (RIRLO) and East Main Street (LRIRO),
Full access off of Haggerty Lane
Origin/Destination E Main St West of Proposed Site- 40.1% of site generated trips
o Route: E Main St to Highland Blvd Access (50% of entering trips from this
origin/destination, 100% of exiting trips from this origin/destination)
o Route: E Main St to E Main St Access (50% of entering trips from this origin/destination)
Origin/Destination E Main St East of Proposed Site – 23.6% of site generated trips
o Route: E Main St to Haggerty Ln Access (50% of trips from this origin/destination)
o Route: E Main St to E Main St Access (50% of trips from this origin/destination)
Origin/Destination Highland Blvd – 27.4% of site generated trips
o Route: Highland Blvd to Highland Blvd Access (100% of trips from this
origin/destination)
Origin/Destination Haggerty Ln – 9.0% of site generated trips
o Route: Haggerty Ln to Haggerty Ln Access (100% of trips from this origin/destination)
Figure 10 - Alternative 5 Trip Assignment
East Main Street Development Traffic Impact Study 16
Signal Warrant Analysis
Peak hour turning movement volumes including both development generated traffic and existing traffic
volumes can be seen in Figure 11, Figure 12, Figure 13, Figure 14 and Figure 15. These volumes
were used in the signal warrant analyses for each development scenario.
The eight-hour volume, four-hour volume and peak hour volume warrants were met at the intersection
of Haggerty Lane and East Main Street under development traffic conditions. The four-hour and peak
hour volume warrants were also met under background traffic conditions. If left unsignalized this
intersection is expected to operate at LOS “F” during peak hour operations.
No other unsignalized study intersections warranted signalization under development traffic conditions.
East Main Street Development Traffic Impact Study 17
Figure 11 - Alternative 1: 2016 Development Traffic Volumes
East Main Street Development Traffic Impact Study 18
Figure 12 - Alternative 2: 2016 Development Traffic Volumes
East Main Street Development Traffic Impact Study 19
Figure 13 - Alternative 3: 2016 Development Traffic Volumes
East Main Street Development Traffic Impact Study 20
Figure 14 - Alternative 4: 2016 Development Traffic Volumes
East Main Street Development Traffic Impact Study 21
Figure 15 - Alternative 5: 2016 Development Traffic Volumes
East Main Street Development Traffic Impact Study 22
Intersection Capacity Analysis Results
Intersection capacity analyses were performed for weekday AM peak hour and PM peak hour traffic
conditions at all study intersections under the 2016 completed development scenario. (See Table 7)
Capacity analyses were performed for the following site access alternatives:
Alternative 1: Full accesses off of Highland Boulevard, East Main Street and Haggerty Lane
Alternative 2: Full accesses off of Highland Boulevard and Haggerty Lane (no development
access on East Main Street)
Alternative 3: Restricted access (RIRO) off of Highland Boulevard, Full accesses off East Street
and Haggerty Lane
Alternative 4: Restricted access (RIRO) off of Highland Boulevard and East Main Street, Full
access off of Haggerty Lane
Alternative 5: Restricted access off of Highland Boulevard (RIRLO) and East Main Street
(LRIRO), Full access off of Haggerty Lane
Existing Alternative
1
Alternative
2
Alternative
3
Alternative
4
Alternative
5
OverallOverallOverallOverallOverallOverall
BBBBBB
13.4 14.8 15.5 14.5 15.1 14.8
BBCBBB
17.0 17.8 21.1 17.2 19.6 19.2
AAAAAA
1.1 0.7 0.8 0.7 0.6 0.6
AAAAAA
1.2 1.1 1.2 1.1 0.9 1.1
AAAAAA
0.4 0.7 0.7 0.7 0.7 0.7
AAAAAA
0.2 0.4 0.4 0.4 0.4 0.4
ABBBBB
2.7 12.1 11.9 11.9 13.2 12.1
ABBBBB
7.1 12.2 13.8 11.6 12.2 11.9
A AAA
2.1 2.2 1.9 2.1
A AAA
3.1 3.4 2.1 2.4
AAAAA
1.2 1.8 1.1 0.8 1.0
AAAAA
2.8 4.9 2.3 1.9 2.2
AAAAA
1.0 1.2 1.0 1.1 1.0
AAAAA
1.9 2.9 1.7 2.1 1.7
Highland Boulevard
&
East Curtiss Street
AM Peak
PM Peak
Intersection Time
Period
East Main Street
&
Highland Boulevard
AM Peak
PM Peak
East Main Street
&
Cypress Street
AM Peak
PM Peak
East Main Street
&
Haggerty Lane
AM Peak
PM Peak
Development Access
&
Haggerty Lane
AM Peak
PM Peak
Development Access
&
East Main Street
AM Peak
PM Peak
Development Access
&
Highland Boulevard
AM Peak
PM Peak
Table 7 - 2016 Development Scenario Intersection Capacity Analysis Results
East Main Street Development Traffic Impact Study 23
All study intersections were found to perform above minimum standards for each alternative. However,
deficient delay is expected for several intersection approaches and intersection movements.
Under Alternative 1 conditions, the Haggerty Lane and East Main Street intersection eastbound left-turn
movements are expected to experience 39.4 seconds of delay (LOS “D”) during AM Peak hour
operations. Deficient level of delay (35.1 s, LOS “E”) is also expected for left-turning vehicles exiting
the development at the East Main Street access during PM peak hour operations.
Under Alternative 2 conditions, the Highland Boulevard and East Main Street intersection is expected
to operate at LOS “B” during the AM peak hour and LOS “C” during the PM peak hour. During PM peak
hour conditions, traffic is expected to cause deficient levels of delay (35.5 s, LOS “D”) for westbound
left-turn movements. These delays are likely linked to the additional vehicles using Highland
Boulevard to enter and exit the development instead of an East Main Street access. The increased
traffic volumes on Highland Boulevard under Alternative 2 conditions are also expected to cause
deficient levels of delay (34.1 s, LOS “D”) for left-turning vehicles exiting the development at the
Highland Boulevard access.
Alternative 3 is also expected to experience deficient delay (39.8 s, LOS “E”) for left-turning vehicles
exiting the development at East Main Street during PM peak hour operations. This increase in delay for
left-turning exiting vehicles leads to deficient levels of delay for the northbound approach (25.9 s, LOS
“D”).
Alternative 4 is not expected to experience deficient levels of delay at any of the study intersections,
approaches or movements.
Alternative 5 is not expected to experience deficient levels of delay at any of the study intersections,
approaches or movements.
A summary of the proposed alternatives’ benefits and weaknesses is provided in Table 8.
Detailed capacity analysis results are provided in Appendix B.
East Main Street Development Traffic Impact Study 24
Table 8 – Alternatives’ Benefit & Weakness Summary
Benefits Weaknesses
Alternative 1
Full accesses off of Highland Boulevard, East Main Street and Haggerty Lane
Full accesses off East Main Street,
Highland Boulevard, and Haggerty Lane.
Haggerty Lane and East Main Street intersection
eastbound left-turn movements experience 39.4
s delay (LOS “D”) during AM peak hour
conditions.
East Main Street access northbound left-turn
movements experience 35.1 s delay (LOS “E”)
during PM peak hour conditions.
Alternative 2
Full accesses off of Highland Boulevard and Haggerty Lane (no development access on East Main Street)
No private access onto East Main Street Highland Boulevard access westbound left-turn
movements experience 34.1 s delay (LOS “D”)
during PM peak hour conditions.
Highland Boulevard and East Main Street
intersection westbound left-turn movements
experience 35.5 s delay (LOS “D”) during PM
peak hour conditions.
No access from East Main Street.
Alternative 3
Restricted access (RIRO) off of Highland Boulevard, Full accesses off East Main Street and Haggerty Lane
East Main Street access northbound left-turn
movements experience 39.8 s delay (LOS “E”)
during PM peak hour conditions.
East Main Street access northbound approach
experience 25.9 s (LOS “D”) of total delay during
PM peak hour conditions.
Alternative 4
Restricted access (RIRO) off of Highland Boulevard and East Main Street, Full access off of Haggerty Lane
This alternative is not expected to
experience deficient levels of delay at any
of the study intersections.
Access for development traffic wanting to head
south on Highland Boulevard is convoluted due to
left turns prohibited from exiting the Highland
Road and East Main Street accesses.
Access into the development for cars travelling
west on East Main is limited to Haggerty Lane.
Alternative 5
Restricted access off of Highland Boulevard (RIRLO) and East Main Street (LRIRO), Full access off of
Haggerty Lane
This alternative is not expected to
experience deficient levels of delay at any
of the study intersections.
Resolves weaknesses attributed to
Alternative 4.
Restricted access configurations require special
median or channelization treatments to control
traffic movements. These can increase
maintenance.
East Main Street Development Traffic Impact Study 25
Access Spacing Analysis
The proposed site plan shows single accesses centrally located in the development connecting to
Highland Boulevard and East Main Street. This equates to one new access onto Highland Boulevard and
four fewer accesses onto East Main Street. Two accesses are proposed onto Haggerty Lane, which
matches the number of accesses present at this time. The northern access onto Haggerty Lane is
proposed to be moved south to provide further separation from the Main Street intersection. No access
connection from the development to the existing private road across from East Curtiss Street is being
proposed due to grade issues.
The existing 465 ft on East Main Street between Highland Boulevard and Haggerty Lane only allows 213
feet and 237 feet between accesses under the current site plan (See Figure 2). This does not provide
the minimum access spacing distance prescribed by Bozeman city code. According to the code,
development access would require 660 ft for a full access or 315 ft for a partial access.
A Highland Boulevard access requires 660 ft of spacing distance for a full access or 315 ft of spacing
distance for a partial accesses under city code. A distance of approximately 545 ft is available between
East Main Street and East Curtiss Street. The proposed access provides 327 feet or separation from
East Main Street and 197 feet of separation from East Curtiss Street. Assuming partial access, it is
possible to satisfy the minimum spacing requirements between a Highland Boulevard development
access and East Main street, however, this access would fail to meet minimum spacing requirements
with East Curtiss Street.
The proposed full accesses on Haggerty Lane do not meet the minimum 330 ft spacing for full access on
collector streets. One planned access is located approximately 146 ft south of East Main Street and the
proposed J & H Inc. access is located only 32 ft north of the alley and 60 ft south of the other proposed
site access.
The Haggerty Lane accesses were analyzed as a single access. The Haggerty Lane access was evaluated
to determine the level of benefit that could be seen by using left and right turn lanes. Left and Right
turn lanes at the Haggerty exit only reduce delay from 12.0 to 11.4 s. The northbound lane only
experiences 1.2 s of delay and 3.0 s delay for LT vehicles. Therefore, insufficient benefit was realized
by the addition of left and right turn lanes at the driveway for the development. Proposed
development access spacing can be seen in Figure 2.
Other Access Spacing Considerations
Aside from concerns regarding access to the proposed development, there are other private accesses
across from the development and along both Highland Boulevard and East Main Street (See Figure 1).
These private accesses currently have full access and do not meet minimum access spacing distances
found in the Bozeman city code. If access to the proposed development were to be restricted, many of
these existing establishments could have impacts to their own level of access.
Queuing Analysis
Queues from the capacity analysis were used to determine whether there will be potential issues with
proposed access spacing. Under average peak hour queuing conditions the proposed development
accesses are not expected to experience any blockage. However, under 95th percentile queuing
conditions access blockages become an issue for the following turning movements:
Right-turning vehicles entering and exiting at the Highland Boulevard access
Left-turning vehicles entering and exiting at the northern Haggerty Lane access
All vehicles exiting at the East Main Street access.
Left-turning vehicles entering the East Main Street access
East Main Street Development Traffic Impact Study 26
Queues for the westbound left-turn movements at the Haggerty Lane and East Main Street intersection
are expected to exceed the existing 65 ft left-turn bay length. 95th percentile queues for the
westbound left-turn movements are expected to be approximately 110 ft long during peak hour
conditions while average queues are expected to be 70 ft.
Anticipated average and 95th percentile queues at the study intersections are shown in Figure 16,
Figure 17 and Figure 18. Full queuing details can be found in Appendix D.
Figure 16 – Alt 1 & Alt 2 Anticipated Queuing
East Main Street Development Traffic Impact Study 27
Figure 17 - Alt 3 & Alt 4 Anticipated Queuing
East Main Street Development Traffic Impact Study 28
Bicycle and Pedestrian Facilities
On-street bicycle facilities are currently located on both sides of the East Main Street and Haggerty
Lane roadways. Sidewalks running along East Main Street conclude at Highland Boulevard on the
southern side and between Highland Boulevard and Haggerty Lane on the northern side. A shared-use
path runs along the western side of Highland Boulevard.
The proposed site plan shows how sidewalks are proposed to connect to building and parking areas
within the development. The site plan also shows sidewalks proposed along Highland Boulevard, East
Main Street and Haggerty Lane which may connect to existing and future sidewalk facilities off-site.
Concerns have been voiced by local citizens regarding safety for pedestrians and bicyclists crossing
Highland Boulevard. It is recommended that these crossings continue to be promoted at the East Main
Street traffic signal and at the crossing located south of East Curtiss Street.
Figure 18 - Alt 5 Anticipated Queuing
East Main Street Development Traffic Impact Study 29
RECOMMENDATIONS
Warranted signalization of the Haggerty Lane and East Main Street intersection is recommended as it
would reduce delay and improve LOS under both existing and development conditions. Signalization
would greatly improve the northbound approach from LOS “E” under existing PM peak hour stop-
controlled conditions to LOS “B” under development PM peak signalized conditions. Each alternative
analysis assumes the signalization of the intersection of Haggerty Lane and East Main Street. If this
intersection was left unsignalized, it would result in higher delays and operate at LOS “F”.
Based on the analysis conducted on five alternatives for access to the development, it is recommended
that further discussions with the city of Bozeman and MDT be undertaken to determine the desired
access alternative for implementation. It is recommended that three alternatives be further discussed:
Alternative 1: Alternative 1 is preferred by the developer and would be the easiest to implement. It
does create issues with LOS at multiple locations and falls furthest from meeting Bozeman city code for
access spacing. However, it is the only alternative that would not have potential impacts to other
private establishments’ access across the road along both Highland Boulevard and East Main Street.
Alternative 4: Alternative 4 provides the best traffic operations for all adjacent roadways and comes
closest to meeting Bozeman city code for access spacing. However, access to the development from
the east is limited to Haggerty Lane, and traffic leaving the development to travel south on Highland
Boulevard must either use the Haggerty Lane exit or find some other route/U-turn to access Highland
Boulevard.
Alternative 5: Alternative 5 provides good traffic operations for all adjacent roadways and provides
slightly less access restrictions than Alternative 4. Access to and from the development is superior to
Alternative 4 as traffic to and from all directions has good options for entering and leaving the site.
It is recommended that Alternative 2 and Alternative 3 be eliminated from further consideration due to
LOS impacts and minimal benefits in comparison to the other alternatives.
The proposed site plan shows how sidewalks are proposed to connect to building and parking areas
within the development. The site plan also shows sidewalks proposed along Highland Boulevard, East
Main Street and Haggerty Lane which may connect to existing and future sidewalk facilities off-site. It
is recommended that sidewalks be installed as is shown in the proposed site plan.
Concerns have been voiced by local citizens regarding safety for pedestrians and bicyclists crossing
Highland Boulevard. It is recommended that these crossings continue to be promoted at the East Main
Street traffic signal and at the crossing located south of East Curtiss Street.