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Home My WebLink About006.01 - Appendix E.1 - TIS Amendment Memo P.O. Box 249 Bozeman, MT 59771 406.922.7300 www.406traffic.com M E M O R A N D U M To: Peter Andrews, Intrinsik Architecture From: Nate Larson, PE, PTOE, RSP1 Date: 8/14/2026 Subject: Boutique Hotel Mendenhall, TIS Validation This memo provides updated information to supplement the original Traffic Impact Study (TIS, October 2024) for Intrinsik’s boutique hotel project on Mendenhall Street in Bozeman. Its purpose is to assist the project team with its amended project application to the City by showing why the traffic impact conclusions documented in that TIS, based on 71 rooms, should still be considered valid even if a higher number of rooms is proposed. The context is a BMC requirement (38.740.120.B.2) that the amended project demonstrate substantial compliance with the originally approved plan. It reads, “Changes proposed for the site, singly or cumulatively, do not increase by more than 20% any of the following: lot coverage by buildings, storage areas, parking areas or impervious surfaces, and/or do not result in an increase in intensity of use as measured by traffic generation, stormwater discharge, or other measurable off-site impacts.” The original TIS for BHM indicated that no intersection traffic impacts requiring operational mitigation, such as changing traffic control type or adding capacity, would result. To help inform your project development effort, I’ve conducted additional analysis of the hotel project with specific regard to the “traffic generation” element of the aforementioned code requirement. With the project modification proposed, traffic generation will be equal to or less than the level documented in the original TIS, because the way it is calculated has changed since the original project proposal. This big-picture industry change was not a factor in the project team’s decision to modify the hotel size proposed. A major change occurred in the field of traffic impact analysis recently. The Institute of Transportation Engineers (ITE) overhauled its Trip Generation guidance since the original BHM TIS was published. The original TIS used ITE’s 11th edition. In the summer of 2025, ITE issued a substantial update of the Trip Generation product, in the form of the 12th edition, and no longer supports the 11th. The ITE’s 12th edition trip generation assumptions for the Hotel land use (such as which supporting onsite facilities are often included) and its daily traffic generation data summary chart are appended to this memo. PTOE #1185, certified since 2003 406 Traffic & Transportation Consulting Intrinsik: BHM TIS Validation, 8/13/2026 2 The most prominent change to trip generation, and the most relevant to this project, was ITE’s elimination of older trip generation studies contributing to the data set. Specifically, data from studies conducted in the 1980s and earlier are no longer used to estimate trip rates, such that all rates are now based on site studies from the 1990s and later. In the case of the “Hotel” land use, this change resulted in a somewhat lower trip generation rate in the 12th edition than in the 11th. ITE’s direction for the traffic engineering community to stop using the older edition of its guidance when a new one is issued is very typical. Calculating trips using the old rate is not considered a valid procedure after a new rate replaces it. Only one rate must be used for the project because the estimation of trip generation does not allow for the possibility that individual rooms or groups of rooms within a single hotel will generate trips at different rates, or for those rates to vary based on when a calculation occurs. The additional analysis I have conducted is to calculate the number of rooms that would generate the same number of trips as were indicated in the original BHM TIS by dividing those that trip total by the new ITE 12th edition rate. This analysis has produced a maximum number of hotel rooms for which the original TIS findings remain valid. In the following table, the older rate and daily trip total is shown in red text while the latest information is shown in blue text. Note that parking needs and valet trips are a function of the trip total, so they would remain the same if trips also do not change. Rates, Trips and Rooms ITE Hotel Daily Trip Rate, 11th Edition: 7.99 trips per room Total for 71 rooms (7.99 ͯ 71) = 567 daily trips ITE Hotel Daily Trip Rate, 12th Edition: 5.84 trips per room Number of rooms supported (567 ÷ 5.84) = up to 97 rooms As of the date of this memo, 91 rooms are proposed for the hotel. At the current ITE trip rate this translates to an estimated average number of trips per typical weekday of 531, or a reduction of about 6%. For this reason, from a traffic generation standpoint the amended project is substantially compliant with the originally approved plan. A new, updated TIS would show the same or lower traffic impacts and therefore should not be necessary. If you have any questions about this memo, please feel free to reach out to me directly at 406.922.7300 or nate@406traffic.com. Land Use: 310Hotel Description A hotel is a place of lodging that provides overnight accommodation and supporting facilities such as a full-service restaurant, concierge service, valet parking, cocktail lounge, meeting rooms, banquet room, and convention facilities. A hotel typically provides a swimming pool or another recreational facility such as a fitness room. Additional Data Some properties in this land use provide guest transportation services (e.g., airport shuttle, limousine service, golf course shuttle service) which may have an impact on the overall trip generation rates. The sites were surveyed in the 1990s, the 2000s, the 2010s, and the 2020s in California, District of Columbia, Delaware, Florida, Indiana, Minnesota, New Jersey, Ontario (CAN), Pennsylvania, South Dakota, Vermont, and Washington. Trip generation at a hotel may be related to the presence of supporting facilities such as convention space, restaurants, meeting/banquet space, and retail facilities. Future data submissions should specify the presence of these amenities. Reporting the level of activity at the supporting facilities such as full, empty, partially active, number of people attending a meeting/banquet during observation may also be useful in further analysis of this land use. Source Numbers 357, 507, 577, 728, 867, 872, 925, 951, 1009, 1021, 1026, 1046, 1219, 1222, 1224 494 Trip Generation Manual, 12th Edition • Volume 3 Hotel(310) Vehicle Trip Ends vs:Rooms On a:Weekday Setting/Location:General Urban/Suburban Number of Studies:2 Avg.Num.of Rooms:143 Directional Distribution:50%entering,50%exiting Vehicle Trip Generation per Room Average Rate Range of Rates Standard Deviation 5.84 5.58 -6.03 *** Data Plot and Equation Caution –Small Sample Size 0 100 2000 1000 2000 Average RateStudySite Fitted Curve Equation:Not Given R²=*** X =Number of RoomsT = Trips EndsGeneral Urban/Suburban and Rural (Land Uses 000–399)495