HomeMy WebLinkAbout07-Mill Bldg Reno Traffic Study
October 3, 2024
Doug Minarik
Minarik Architecture
618 N Wallace Ave #2
Bozeman, MT 59715
Reference: Trip Generation Letter – Mill Building Renovation
Project No. 06020.12
Dear Doug:
The purpose of this letter is to provide trip generation estimates for the proposed
renovation of and addition to the Mill Building located north of East Cottonwood
Street between North Wallace Avenue and North Ida Avenue in Bozeman, Montana.
The site plan proposes to renovate the 2,200 square-foot Mill Building, which is
currently vacant. Construction of a 5,300 square-foot addition is also proposed to the
north of the existing building. It is anticipated that the existing building and addition
will include gallery space to show art exhibits, as well as community center uses
which include flex-use spaces, offices, conference rooms, and restrooms.
The trip projection analysis utilized Trip Generation, 11th Edition, published by the
Institute of Transportation Engineers (ITE), which is the most widely accepted source
for determining trip generation projections. Recreational Community Center – Land
Use 495 was found to be the most representative land use within the Trip Generation
database and was used to calculate the AM and PM peak hour trip generation
estimations for the building. Projected trip generation values for the proposed site
are shown in Table 1 below.
In total, 216 gross new trips are expected to be generated on an average weekday, with
14 gross trips during the AM peak hour and 19 gross trips during the PM peak hour.
Table 1: Mill Building Renovation Trip Generation Summary
Intensity Units total enter exit total enter exit total enter exit
7.50 1000 SF GFA 216 108 108 14 9 5 19 9 10
36 18 18 2 1 1 3 1 2
216 108 108 14 9 5 19 9 10
36 18 18 2 1 1 3 1 2
180 90 90 12 8 4 16 8 8
(1) Recreational Community Center - Land Use 495* Units = 1000 SF GFA
Average Weekday: Average Rate = 28.82 (50% entering/50% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 7 and 9 AM: Average Rate = 1.91 (66% entering/34% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 4 and 6 PM: Average Rate = 2.50 (47% entering/53% exiting)
*Trip Generation, 11th Edition , Institute of Transportation Engineers, 2021
†Bozeman Transportation Master Plan, Table 2.3, City of Bozeman, 2017
Total Altos Photonics External Trips
Total Gross Trips
Mill Building Renovation and Addition1
Total Multimodal Reductions
Multimodal Reductions (16.6%)†
PM Peak HourAverage WeekdayIndependent Variable AM Peak HourLand Use
Mr. Doug Minarik
October 3, 2024
Page 2
Trip generation projections provide an estimate of the total number of trips that
would be generated by a proposed development. However, in order to estimate the net
number of new trips made by personal vehicles external to the site, adjustments
must often be made to account for internal capture trips, pass-by trips, and trips
made by alternate modes.
Internal capture (IC) trips do not have origins or destinations external to a project
site. Since IC trips occur internally, they do not have an impact on external traffic
operations. IC trips most often occur in mixed-use developments where residential,
commercial, and office-related land uses exhibit a high rate of internal trip exchange.
Although there may be some internal trip capture between the Mill Building and
adjacent developments, IC trips were not calculated for this analysis.
Pass-by trips are made as intermediate stops on the way from a point of origin to a
primary trip destination. Pass-by trips are attracted from traffic “passing by” on an
adjacent street that offers direct access to the site and are primarily attracted by
commercial type land uses and were therefore not calculated for this analysis.
A portion of the external trips generated by the Mill Building Renovation are expected
to be made by alternate modes (walking, biking, and transit), thereby reducing
vehicular trips generated. There are sidewalks accessing the site from all directions
and access to a nearby trail system. A 16.6 percent reduction for multimodal travel
was applied to gross trips to determine new external vehicle trips. This reduction was
determined by totaling walking and biking commuter percentages summarized in
Table 2.3 in the 2017 Bozeman Transportation Master Plan (TMP).
With the multimodal reduction applied, the renovated Mill Building and addition are
projected to generate a total of 180 new external average weekday trips (90 entering/
90 exiting) with 12 trips (8 entering/4 exiting) generated during the AM peak hour and
16 trips (8 entering/8 exiting) during the PM peak hour.
If you have any questions or concerns, please feel free to contact me at 406-922-4326
or astoltzfus@sanbell.com.
Sincerely,
Audrey Stoltzfus, PE, RSP2I
Project Engineer
ARS/jhs/SG
Enc.
P:06020.12_Tinworks_Pre_Design_10.3.2024