HomeMy WebLinkAbout16 - Traffic Impact Study - Water Lilly Condos •
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June 28, 2016
traffic Mike Balch, P.E.
Services C&H Engineering and Surveying, Inc.
1091 Stoneridge Drive
Bozeman, MT 59718
RE: Norton East Ranch Condominiums Traffic Impacts
Dear Mike,
It is my understanding that the City of Bozeman has requested a re-evaluation of the
traffic impacts for the Norton East Ranch Subdivision at the intersection of Cottonwood
Road and Babcock Sheet based on changes to proposed land uses within the
development. The developers of the Norton East Ranch propose to change Phase 1 Lot 1
(0.412 acres) from four multi-family units to four condominium units (Majesto
Condominiums). Additionally Phase 2A Lot IA (1.483 acres) is proposed to change
from 5 lots with 4 single family units each(20 total single family units) to 14
condominium(Destin Condominiums). These proposed changes would create a decrease
of 6 residential units within the Norton East Ranch Development. The subject lots are
located south of Babcock Street at Waterlily Drive.
Generally condominium units create fewer daily and peak-hour trips than a typical single-
family unit. ATS performed a trip generation analysis to determine the change in trip
generation from the proposed change in land use using the trip generation rates contained
in Trip Generation (Institute of Transportation Engineers,Ninth Edition). These rates are
the national standard and are based on the most current information available to planners.
A vehicle "trip" is defined as any trip that either begins or ends at the development site.
According to the ITE trip generation rates in total the new condominiums would produce
8 AM peak hour trips, 9 PM peak hour trips, and 104 daily trips compared to the 18 AM
peak hour trips, 24 PM peak hour trips, and 230 daily hips for the original single-family
lots. In total, the trip generation from the Norton East Ranch Subdivision would decrease
by 10 AM trips, 15 PM trips, and 126 daily trips with the proposed land use changes.
The trip generation rates and totals are shown in Table 1.
A traffic impact study produced by ATS for the Cottonwood Corner Apartment in June
2016 suggested that the intersection of Cottonwood Road and Babcock Street is currently
operating at LOS C. This is consistent with LOS conditions calculated for the
intersection in the Bozeman Transportation Master Plan. The Cottonwood Corner
Apartments TIS also suggested that the intersection would operate at LOS C in the future
with traffic from the Cottonwood Corner Apartments taking into account the ongoing
construction of the Norton East Ranch Subdivision. The LOS at the intersection would
obviously improve slightly with the lower trip generation rate from the proposed land use
changes.
130 South Howie Street
Helena, Montana 59601
406-459-1443
Table 1 - 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
Existing
Single-Family
Residential 24 0.75 18 1.01 24 9.57 230
Proposed
Majesto
Condominiums 4 0.44 2 0.52 2 5.81 23
Destin
Condominiums 14 1 0.44 1 6 0.52 7 5.81 81
Difference 10 15 126
The decrease in projected traffic volumes from the proposed changes to the North East
Ranch development will have a net positive impact on the projected future traffic
operations at the intersection of Babcock Street and Cottonwood Road. No mitigation
measures are recommended at this time.
Sincerely,
Bob Abelin, P.E. PTOE
Abelin Traffic Services, Inc.
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