HomeMy WebLinkAboutAppendix C - Traffic Impact Memo - 03-24-2021
130 South Howie Street
Helena, Montana 59601
406-459-1443
March 24, 2021
Ryan Hudock, P.E.
C&H Engineering
1091 Stoneridge Dr
Bozeman, MT 59718
RE: Norton Condos/Apartments Traffic Impact Analysis Update
Dear Ryan, it is my understanding that the City of Bozeman has requested an updated traffic
analysis for the Fallon Apartments and Fallon Condos projects along Fallon Street in Bozeman.
The Fallon Apartments consist of two apartment buildings totaling 36 units and the Fallon
Condos consists of 8 buildings totaling 22 units which were originally part of the Norton East
Ranch Phase 4 development. The City has requested an analysis of the specific impacts of
these projects as they relate to the overall traffic analysis which was performed for this
section of property with the original 2017 Norton East Ranch Phase 4 Residential/ Commercial
Subdivision Traffic Impact Study and the most recent January 2021 Norton East Ranch
Commercial Area Traffic Impact/Signal Warrant Study, both prepared by ATS.
The 2017 Norton East Ranch Phase 4 TIS assumed that the overall development would include
up to 96 residential apartment units plus commercial space. The 2021 Norton East Ranch
Commercial Area Traffic Impact/Signal Warrant Study increased the residential portion of the
project to 306 apartment and condominium units which would be constructed over the next
10 years. The Norton East Ranch Commercial Area would also include a new connection to
Huffine Lane at Laurel Parkway which would be signalized.
These two residential projects would account for 58 of the anticipated 306 residential (19%)
units anticipated for this area and would account for a total of 315 daily vehicle trips (3%) of
the projected 10,000 daily vehicle trips that the Norton East Ranch Commercial Area will
ultimately produce. Peak-hour traffic generation from these two residential projects will be
21 AM peak-hour trips and 26 PM peak hour trips (2-3 minutes between peak-hour vehicle
trips), which would not create any traffic concerns at the approaches to the two projects or
the intersection of Fallon Street and Pond Lily Drive. Most of the traffic from the Fallon
Apartments and Fallon Condos would use Fallon Street to the east to connect with
Cottonwood Road.
Based on 2020 traffic counts conducted by ATS, the intersection of Fallon Street with
Cottonwood Road is currently operating at LOS C in the morning and evening peak traffic
periods. The 2017 TIS for this project area did not anticipate any traffic issues at the nearby
intersection or recommend any roadway improvements with the project. The new 2021
Norton East Ranch Commercial Area Traffic Impact/Signal Warrant Study projected the LOS
at the intersection of Fallon Street with Cottonwood Road will fall to LOS E and LOS F with the
construction of the proposed developments east of Cottonwood Road (Town & Country
grocery store, Icon Apartments, and Ferguson Farm II). These LOS issues were identified in
previous reports for projects in this area including the 2019 Ferguson Farm II TIS and the Icon
Apartments TIS. The Icon Apartments did not recommend any specific mitigation measures
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for the intersection with Cottonwood Road and suggested that a higher form a traffic control
at this location would not be needed with that project. With the additional traffic from
Ferguson Farm II and the Town & Country grocery store, it is likely that a signal will be needed
at the intersection of Cottonwood Road and Fallon Street to meet future traffic demands.
The City of Bozeman should determine if a new traffic signal at the intersection of Fallon
Street and Cottonwood Road fits with the overall corridor development plans for Cottonwood
Road. Generally, traffic signals in this area are located at ½ mile spacing, which provides
effective vehicle progression through the network of existing traffic signals. The distance
from Fallon Street to the Huffine Lane and Babcock Street traffic signals is ¼ mile. Adding a
mid-distance traffic signal is acceptable if needed, but all traffic signals ultimately decrease
the roadway capacity on the main route (Cottonwood Road). If the City of Bozeman wants to
maintain Cottonwood Road as a major north/south arterial route, the number of traffic
signals allowed along the corridor will need to be limited. A traffic signal at Fallon Street
would be more consistent with the major commercial routes in Bozeman along 19th Avenue
and Main Street. Additionally, the east side of Fallon Street may need to be widened at the
intersection to provide enough room for left-turn lanes at a traffic signal and the mailboxes
along the north side of Fallon Street near the intersection would need to be moved to prevent
interruptions in traffic flow if the intersection is signalized. If a traffic signal was erected at
this location, the LOS would improve to B. Traffic from the Fallon Apartments and Fallon
Condos would account for approximately 1-2% of the future traffic volumes at this
intersection.
Overall, we feel that the traffic impact studies for the 2017 Norton East Ranch Phase 4
Residential/Commercial Subdivision and the recent January 2021 Norton East Ranch
Commercial Area Traffic Impact/Signal Warrant Study accurately accounted for the projected
traffic from the 58 residential units proposed at the Fallon Apartments and Fallon Condos.
However, the continued growth which has occurred in this area over the last four years and
the other planned projects in this area have changed the projected traffic volumes and
roadway improvements needs in this area since the projects were originally studied in 2017.
The potential need for the installation of a traffic signal at the intersection of Fallon Street
and Cottonwood Road should be discussed with the City with the understanding that the need
for this signal is primarily tied to the overall development plans for this area and the Fallon
Apartments and Fallon Condos would only account for 1-2% of the projected traffic at this
intersection.
If you have any additional questions please feel free to contact me at 406-459-1443.
Sincerely,
Bob Abelin, P.E. PTOE
Abelin Traffic Services, Inc.