HomeMy WebLinkAbout006_TripGenerationLetter
August 28, 2024
Lucian Hand
Altos Photonics, Inc.
201 S Wallace Ave
Bozeman, MT 59715
Reference: Trip Generation Letter – Altos Photonics Site
Project No. 24141.1
Dear Lucian:
The purpose of this letter is to provide trip generation estimates as well as a detailed
parking analysis for the proposed development to be constructed at 411 E Tamarack
Street in Bozeman, Montana. The site plan proposes to develop an 11,868 square-foot
building with Altos Photonics as the primary business operating on the site, which
will include manufacturing and office spaces. There will also be a small office space
rented out to another tenant as well as a small coffee shop on the site. The site
currently hosts The Perch Vintage & Upcycled Furniture which is included in the
demolition plan. The demolition of this furniture store would reduce existing trips to
the site and result in a lower net impact of trips to the new building.
Trip Generation Analysis
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. Manufacturing – Land Use 140, General
Office Building – Land Use 710, and Coffee/Donut Shop without Drive Through Window
– Land Use 936 were used to calculate the AM and PM peak hour trip generation
estimations for the building. Land Use 140 was used for the manufacturing rooms
and office space for Altos Photonics, Land Use 710 was used for the office space in the
leased area, and Land Use 936 was used for the coffee shop. Projected trip generation
values for the proposed site are shown in Table 1 on the following page.
In total, 542 gross new trips (272 entering/270 exiting) are expected to be generated
to the site on an average weekday, with 93 gross trips (49 entering/44 exiting) in the
AM peak hour and 39 gross trips (17 entering/22 exiting) in the PM peak hour.
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.
Mr. Lucian Hand
August 28, 2024
Page 2
Internal capture (IC) trips are trips that 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 and were therefore calculated between the various uses within
the Altos Photonics site. Although IC trips are not typically calculated for
manufacturing uses, due to the site having office uses within the manufacturing
space and the coffee shop in the same building, some IC trips were assumed
between Altos Photonics and the coffee shop. In total, 30 IC trips were calculated for
an average weekday with four IC trips in the AM peak hour and zero IC trips in the PM
peak hour.
Pass-by trips are trips that 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. Pass-by trips are
primarily attracted by commercial type land uses such as restaurants, convenience
Table 1: Altos Photonics Trip Generation Summary
Intensity Units total enter exit total enter exit total enter exit
10.60 1000 SF GFA 50 25 25 7 5 2 8 2 6
14 5 9 2 1 1 0 0 0
6 3 3 1 1 0 1 0 1
0.35 1000 SF GFA 5 3 2 1 1 0 1 0 1
1 1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0.92 1000 SF GFA 487 244 243 85 43 42 30 15 15
15 9 6 2 1 1 0 0 0
78 39 39 14 7 7 4 2 2
169 84 85 30 15 15 12 6 6
542 272 270 93 49 44 39 17 22
30 15 15 4 2 2 0 0 0
84 42 42 15 8 7 5 2 3
169 84 85 30 15 15 12 6 6
259 131 128 44 24 20 22 9 13
(1) Manufacturing - Land Use 140* Units = 1000 SF GFA
Average Weekday: Average Rate = 4.75 (50% entering/50% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 7 and 9 AM: Average Rate = 0.68 (76% entering/24% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 4 and 6 PM: Average Rate = 0.74 (31% entering/69% exiting)
(2) Small Office Building - Land Use 712* Units = 1000 SF GFA
Average Weekday: Average Rate = 14.39 (50% entering/50% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 7 and 9 AM: Average Rate = 1.67 (82% entering/18% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 4 and 6 PM: Average Rate = 2.16 (34% entering/66% exiting)
(3) Coffee/Donut Shop without Drive-Through Window - Land Use 936* Units = 1000 SF GFA
Average Weekday: Average Rate = 531.44 (50% entering/50% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 7 and 9 AM: Average Rate = 93.08 (51% entering/49% exiting)
Weekday, Peak Hour of Adjacent Street Traffic , One Hour Between 4 and 6 PM: Average Rate = 32.29 (50% entering/50% exiting)
*Trip Generation, 11th Edition, Institute of Transportation Engineers, 2021
**Trip Generation Handbook, 3rd Edition, Institute of Transportation Engineers, 2017
†Bozeman Transportation Master Plan, Table 2.3, City of Bozeman, 2017
PM Peak HourAverage WeekdayIndependent Variable AM Peak HourLand Use
Total Altos Photonics External Trips
Total Gross Trips
Total Internal Capture Trips
Altos Photonics1
Tenant Office Space2
Internal Capture Trips**
Coffee Shop3
Internal Capture Trips**
Total Pass-By Trips
Total Multimodal Reductions
Multimodal Reductions (16.6%)†
Multimodal Reductions (16.6%)†
Internal Capture Trips**
Multimodal Reductions (16.6%)†
Pass-By Trips** (Avg. Rate = 43%)
Mr. Lucian Hand
August 28, 2024
Page 3
markets, and gas stations. Pass-by rates for Manufacturing, General Office Building,
and Coffee/Donut Shop without Drive-Through Window are not provided in the ITE
Trip Generation Manual. However, it is likely that some pass-by trips may occur to the
coffee shop on the site, so pass-by rates for High-Turnover (Sit-Down) Restaurant –
Land Use 932 was used to estimate pass-by trips to the coffee shop. A total of 169
weekday pass-by trips are projected for the coffee shop, with 30 trips during the AM
peak hour and 12 trips during the PM peak hour.
A portion of the external trips generated by Altos Photonics development 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 a bike lane along Rouse Avenue. A reduction of 16.6 percent for
multimodal commuting was applied to the gross trips to determine total new
external vehicle trips. This reduction was determined by totaling percentages of
commuters using other modes such as walking or biking which is summarized in
Table 2.3 in the 2017 Bozeman Transportation Master Plan. A total of 84 daily
multimodal trips are projected for the site, with 15 multimodal trips in the AM peak
hour and five multimodal trips in the PM peak hour.
With the reductions described above, the Altos Photonics site is projected to
generate a total of 259 new external average weekday trips (131 entering/128 exiting)
with 44 trips (24 entering/20 exiting) generated during the AM peak hour and 22 trips
(nine entering/13 exiting) during the PM peak hour. The demolition of the furniture
store on the current site would also reduce existing trips and result in a lower net
impact of trips to the new building.
Parking Analysis
Section 38.540.050 of the Bozeman Unified Development Code (UDC) outlines the
number of parking spaces required for various uses, with usable floor area as the
unit. Following Table 38.540.050-3 of the UDC, 21 total required parking spaces were
calculated. Adjustments were then made based on the City’s allowable reductions for
bicycle parking (10 percent reduction). With this reduction applied, a total
requirement of 19 vehicle parking spaces was calculated. The Americans with
Disabilities Act (ADA) requires one accessible parking space per 25 total parking
spaces, so one stall will need to meet the ADA standards and be van accessible with
an access aisle.
In total, the UDC requires six bike stalls for this development: two covered bicycle
parking spaces are to be provided for each automobile space not provided per the
reduction noted above (four total spaces), and two bicycle spaces are required based
on Section 38.540.050.A.4. The four bicycle spaces provided to achieve a parking
Mr. Lucian Hand
August 28, 2024
Page 4
reduction are required to be covered, and the reduction also requires a non-
residential shower, changing area, and five clothing lockers to be provided on-site.
The Altos Photonics site plan includes six bicycle parking spaces as well as the
required shower and changing areas.
Table 2 below provides a summary of the code-required parking calculations. It is
important to note that the UDC utilizes usable floor area in square-feet as the
independent variable for calculating parking demand. This is calculated by removing
hallways, other circulation areas, storage and mechanical rooms, and bathrooms
from the gross square footage of a building. In contrast, trip generation and parking
generation rates developed by ITE are based on gross floor area, as that was the
variable used in calculating those rates.
Parking requirements were also analyzed utilizing the Parking Generation Manual, 6th
Edition (2023) published by the Institute of Transportation Engineers (ITE). The same
land uses from the trip generation were utilized for the parking analysis. For the ITE
Parking Generation Manual-based calculations the gross floor area was utilized as the
independent variable. Using this method, it was found that 20 parking spaces would
be required for the Altos Photonics site during the average weekday. Table 3 on the
following page shows the calculations based on this method.
Table 2: Altos Photonics Bozeman Code of Ordinances Parking Requirement Summary
Site Use Type
Usable
Floor Area
(SF)
Parking
Rate*
Employees
on maximum
working shift
Parking Rate/
Employee*
Parking
Spaces
Required
Manufacturing & Industrial Uses 3623 1/1000 SF 11 1/2 employees 9.1
Offices 350 1/250 SF -- --1.4
Restaurants, cafes, bars 510 1/50 SF -- --10.2
21
2
19
Spaces Provided 19
*Bozeman, Montana - Code of Ordinances, Section 38.540.050 - Number of parking spaces required. 2011
Altos Photonics
Site
Bozeman, MT Code of Ordinances Parking Requirements
Total Spaces Before Reductions
Covered Bike Parking/Shower Reduction (10%)
Total Spaces Required (City of Bozeman)
Mr. Lucian Hand
August 28, 2024
Page 5
ITE’s Parking Generation Manual also provides average weekday time-of-day
distribution tables for parking demand. Applying Code-required parking demand and
ITE parking demand totals, the peak hour for parking was found to be from 8:00 –
9:00 AM with a maximum demand of 17 parking spaces using both methods. Based
on these results and the above calculations, the total number of spaces proposed to
be provided (19) meets the maximum number of parking spaces required on an
hourly basis by the City code-based, proposed code-reduced, and ITE time-of-day
methods. Table 4 below illustrates the time-of-day distribution calculations.
Table 3: Altos Photonics ITE Parking Generation Requirement Summary
ITE Land Use
Gross
Floor
Area (SF)
Weekday Avg
Parking Rate
Weekday
Parking Spaces
Required
Manufacturing (140) 10602 0.92/1000 SF 10
Small Office Building (710) 350 1.85/1000 SF 1
Coffee/Donut Shop without Drive-Through Window (936) 916 10.36/1000 SF 9
20
ITE Parking Generation
Total Spaces Required (ITE)
Table 4: Altos Photonics Time-of-Day Parking Generation Requirement Summary
12:00 AM 1% 0 0 -- -- -- -- -- -- 0 0
1:00 AM 1% 0 0 -- -- -- -- -- -- 0 0
2:00 AM 1% 0 0 -- -- -- -- -- -- 0 0
3:00 AM 1% 0 0 -- -- -- -- -- -- 0 0
4:00 AM 1% 0 0 -- -- -- -- -- -- 0 0
5:00 AM 5% 1 0 -- -- -- -- -- -- 1 0
6:00 AM 15% 2 1 -- -- -- -- -- -- 2 1
7:00 AM 55% 6 5 -- -- -- 73% 7 7 13 12
8:00 AM 76% 8 7 22% 0 0 100% 9 10 17 17
9:00 AM 82% 8 7 66% 1 1 63% 6 6 15 14
10:00 AM 84% 8 8 89% 1 1 57% 5 6 14 15
11:00 AM 85% 9 8 100% 1 1 42% 4 4 14 13
12:00 PM 90% 9 8 87% 1 1 39% 4 4 14 13
1:00 PM 99% 10 9 77% 1 1 27% 2 3 13 13
2:00 PM 100% 10 9 79% 1 1 -- -- -- 11 10
3:00 PM 95% 10 9 84% 1 1 -- -- -- 11 10
4:00 PM 58% 6 5 84% 1 1 -- -- -- 7 6
5:00 PM 36% 4 3 71% 1 1 -- -- -- 5 4
6:00 PM 15% 2 1 16% 0 0 -- -- -- 2 1
7:00 PM 12% 1 1 -- -- -- -- -- -- 1 1
8:00 PM 11% 1 1 -- -- -- -- -- -- 1 1
9:00 PM 9% 1 1 -- -- -- -- -- -- 1 1
10:00 PM 9% 1 1 -- -- -- -- -- -- 1 1
11:00 PM 8% 1 1 -- -- -- -- -- -- 1 1
Hour
Beginning
Total
City
Parking
Demand
% of
Peak
Period
ITE
Parking
Demand
% of
Peak
Period
ITE
Parking
Demand
% of
Peak
Period
Total ITE
Parking
Demand
ITE
Parking
Demand
City
Parking
Demand
Manufacturing (140)Small Office (712)Coffee Shop (936)
City
Parking
Demand
City
Parking
Demand
Mr. Lucian Hand
August 28, 2024
Page 6
The Altos Photonics site is projected to generate 259 total new external trips on an
average weekday with 44 trips generated during the AM peak hour and 22 trips
during the PM peak hour. The current site plan proposes 19 parking spaces which
meets the requirements outlined in the Bozeman Unified Development Code and the
ITE Parking Generation Manual. 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:24141.01_Altos_Photonics_Site_8.28.2024