Trip Generation Rates for Transportation Impact Analyses of Infill Developments

Abstract

This report provides an easy-to-apply process for use by transportation professionals when estimating vehicular trip generation in built-up urban areas, incorporating the effects of site-specific, local, and area-wide land use and transportation characteristics on estimates of vehicular trip generation for proposed infill development. This process is based on the development and application of mode share and vehicle occupancy adjustment factors applied to conventional trip generation estimates using rates published by the Institute of Transportation Engineers. The study details two ways of deriving the adjustment factors: (1) collecting empirical data from proxy sites located in environments that represent the future context of the project being analyzed; and (2) extracting factors from household travel surveys. The product of this research includes two components: (1) a final report that documents the background, research approach, the development and application of methods to estimate infill trip generation, and a recommended verification approach; and (2) a supplemental technical report that details the application of the household travel survey method. The combination of these two components offers a comprehensive analytical approach and a detailed set of application techniques and requirements to estimate infill development trip generation.