Methodology to Gather Multimodal Urban Trip Generation Data

Assessments of the impact of new land use development on the transportation network often rely on the ITE Trip Generation Manual informational report. Current ITE rates generally represent travel behavior for separated, single-use developments in low-density suburban areas. However, a more compact urban form, access to transit, and a greater mix of uses are known to generate fewer and shorter vehicle trips—and quite possibly more trips overall, especially in heavily urbanized areas like Washington, D.C. Local and national interest exists for generating data that expand upon existing trip rates (and similar parking generation rates) to include sites in diverse, dense contexts. The lack of adequate data on multimodal urban trip generation led the District Department of Transportation in Washington, D.C., to develop and test a streamlined methodology that meets the needs of practitioners who are evaluating the transportation impacts of new developments in dense, multimodal environments. This methodology focuses on capturing all trips to and from a site and the mode of all travelers, not just personal vehicle trips. The methodology was tested at mixed-use multifamily residential buildings but is intended for future use at a wide range of sites. This paper presents the methodology and rationale for a robust national data collection effort.