Cities are increasingly wanting to assess the impacts of new development have on all modes in the transportation system. Many communities are requiring site-level transportation impact analysis to examine travel outcomes. The historical focus on developing data and methods exclusively for the automobile, such as the Institute of Transportation Engineers (ITE) Trip Generation Handbook, has left planners with little guidance for these new challenges. This study aims to examine the limitations in the dominant approaches to understand how they may misguide the planning process for multifamily housing development. Specifically, we aim to examine the vehicle and person trip generation rates associated with the land use taxonomies in the ITE Trip Generation Handbook to differentiate between various kinds of residential housing. We ask:
1. Does the built environment vary across the various ITE Land Use Codes for multifamily housing?
2. How do vehicle trip rates and newly established person trip rates vary across urban locations?
3. How well does ITE’s recommended practice of converting their vehicle trip rate data to person trip rates perform?
To do this, we conducted a national study of multifamily housing sites that makes use of archived transportation counts and intercept surveys collected on site. The study leveraged several concurrent or recent trip generation studies in Portland, OR; San Francisco, CA; Los Angeles, CA; and Washington, DC. The data collected from these sites are analyzed using multivariate statistical techniques. This report concludes with discussion of the implication of these findings for multimodal transportation impact analysis of new development and policies that aim for better coordination between urban land use change and transportation investments.