In June, we presented a webinar about Travel Demand Management Plans (TDMPs) and our approach to these types of studies (view it and others here). A listener reached out to us afterward with a new plan from Montgomery County in Maryland. Their recently updated Local Area Transportation Review (LATR) Guidelines are intended for the preparation and review of transportation impacts studies for development within the County. More context-sensitive and multi-modal procedures, along with revised analysis methods, are specified within this document.
As their LATR is related to our TDMPs, and the fact that we are always interested in seeing how others approach the subject, we have reviewed the guide and share the three most unique ideas below:
1. Trip Generation reductions based on land uses and location within the county
The County provides a table, Appendix Table 1A, which provides pre-determined percentages to apply to ITE trip generation rates based on the location of the development within the county, as well as the land use of the development. These adjustment factors range from 61% to 102%. This idea recognizes the differences between rural, suburb, and urban areas and attempts to adjust expected traffic accordingly.
2. Trip Generation reductions based on non-motorized facility improvements
In order to maintain equal level of service for motorized and non-motorized travel, Montgomery County allows for reductions in trip generation numbers based on additional improvements made to non-motorized facilities. These facilities may include sidewalk, bikeshare stations, bus shelters and benches, bike racks, ADA facilities, etc. It is required that these additional facilities are constructed off-site and within a quarter mile of the development. The equivalent trip reduction for these facilities is equal to one trip per $16,000 spent, with a maximum reduction of 100 trips ($1,600,000 spent on upgraded or new facilities). As most traffic dollars captured from development appears to go toward roadway geometry, this provides some incentive to address non-vehicular infrastructure
3. A maximum peak load of 1.25 riders per seat must be kept for transit systems.
Any development generating 50 peak hour transit riders (based on mode share values in Appendix Table 1B) must ensure all bus routes at stations within 1,000 feet of the site do not have peak loads of over 1.25 riders per seat or a transit Level of Service D. If a development pushes the peak load factor over 1.25, the developer must then work with County staff to add bus and transit improvements equal to the number of additional buses required to return the load to 1.25 riders per seat. This is the stick to the previous item’s carrot, ensuring money is captured beyond the vehicle lanes.
Here’s the link to the to the entire Montgomery County Planning Department 2017 Local Area Transportation Review (LATR) Guidelines. There’s a lot more good information in there that we encourage you to review and incorporate if you don’t already have the same or similar guidelines.
Do you know any States, Counties, Cities, or agencies that have unique standards with respect to Transportation Studies? We would love to hear about them in the comment section below.
We also offer free, open source Trip Generation and Parking data that we collect. We regularly update our Trip Generation data and make it available to anyone who is interested. To download a free copy visit TripGeneration.org.
Jonah Finkelstein, EIT
Jonah received a Bachelor of Civil Engineering from the University of Minnesota Twin Cities in 2013, and was a project engineer for more than two years at Alliant Engineering before joining the Spack Consulting team. He is currently an Engineer in Training (EIT) and leads traffic signal services and traffic studies for clients.
