Reducing demand on the road system by reducing the number of vehicles using the roadways through increasing the number of carpools, vanpools, buses, trains, biking, and walking feasibility.
TDM Plans are based on a simple points system. Projects will generally be required to include TDM measures that total 25 points, with each point roughly equivalent to a 1% reduction in single-occupancy vehicle trips. The Transportation Analysis Handbook includes the full TDM menu and assigns each TDM measure a certain number of points, based on its effectiveness and value.
As originally conceived, the number of points was set at 30, based on greenhouse gas reduction goals in Envision San José 2040. However, after feedback from developers and reviewing the Cost of Development study analysis, this requirement was reduced to 25 points to decrease the burden that the cost of additional TDM may have on the viability of a new development project. Out of the 25 total TDM points required, up to 20 can be achieved based solely on a project’s parking supply.
Types of TDM categories
There are four separate TDM end-use categories. Each has different visitation patterns and, as a result, there are different TDM measures that may be effective for these uses. For example, commute end uses are those that have their most significant traffic impacts at peak commute hours, while visit end uses have more variable transportation demand periods throughout the day. The TDM measures applicable to each of these four use categories are outlined in a city’s “TDM Menu” portion of their Transportation Analysis Handbook:
- Home/HEU (examples: single-family home, apartment, mobile home park)
- Visit/VEU (examples: retail, restaurant, personal services, medical offices)
- Commute End Uses/CEU (examples: office buildings, schools, research & development)
- Other/OTH (examples: warehouse, golf course, transfer station)
- These four different TDM use categories all, described later in this analysis section.