HomeMy WebLinkAbout016 Traffic Review Reponse
October 16, 2025
Taylor Lonsdale, PE
20 E Olive St.
Bozeman, MT 59771
Re: 25067 Velocity Carwash TIS Scoping Letter
MMI#: 10554.001
Dear Taylor:
This letter is to provide written responses to the comments stated in the review memo September 15,
2025. Below are our responses associated with each comment.
Ref #12
The report narrative states that the Trip Generation, 9th Edition was used prior to Table 1 and then states
below Table 1 that the average trip generation rate or equation are based on the 11th edition of the Trip
Generation Manual. Please clarify that the current edition (11th Edition) was used or provide an
explanation as to why the 9th Edition was used.
The report has been revised to reflect the 11th Edition.
Ref #24
Table 1 provides site-generated peak AM and PM hour volumes for ITE land use code (LUC) 948.
However, for the independent variable (IV) of "car wash tunnels" there is only trip generation data
available for peak PM and Saturday. Please clarify how the 74 vehicle trips per tunnel for the peak AM
hour was determined.
The ITE Trip Generation Manual does not provide AM peak hour trip rates for LUC 948 using 'car
wash tunnels' as the independent variable. The 74 vehicle trips per tunnel during the AM peak hour
were estimated using a conservative assumption—typically 50% to 100% of the PM peak hour rate.
This has been changed to 78 to be the most conservative estimate with the information available. This
approach ensures a robust analysis in the absence of direct ITE data.
Ref #24
The tunnel queuing analysis states that the maximum queue length of 12 vehicles is anticipated during the
"weekday midday peak period". There does not appear to be trip generation data available for midday
peak period. Clarify whether the analysis was actually completed based on PM peak period.
This has been revised to indicate PM Peak Period
Ref #26
Provide a more detailed explanation of the methodology used for the queuing analysis. For example, it is
not clear from the reviewer perspective how it was determined that the volume for movement/adjusted flow
rate is 6 vehicles per hour. How does this rate relate to the site-generated traffic provided in Table 1?
Additional information is provided in the report to show methodology for queuing analysis. The most
recent queuing diagram is attached in the report.
Ref #27
The analysis states that a traffic impact study (TIS) was already completed for the development. Please
submit the previously prepared TIS for review. An analysis of the intersection of the proposed site access
with the mall access route and access in front of Petco is of interest to assess the appropriate intersection
control.
The original report didn't mention the original TIS through the site. Per the scoping letter, the city has
obtained a TIS of the Whole Foods (2020) and the Gallatin Valley Mall expansion in 2022
If you should have any questions regarding these comments, revisions and corrections for the Velocity
Carwash don’t hesitate to contact me.
Sincerely,
_____________________________
Celine Saucier, PE
Project Engineer