Microscopic trip generation: Adding fidelity to trip-based travel demand models

In four-step travel demand models, average trip generation rates are traditionally applied to static household type definitions. In reality, however, trip generation is more heterogeneous with some households making no trips and other households making more than two dozen trips. Two improvements for trip generation are presented in this paper. First, the household type definition, which traditionally is based on experience or habituality rather than science, is revised to optimally reflect trip generation differences between household types. For this purpose, over 67 Million household type definitions were analyzed econometrically in a Big-Data exercise. Secondly, a microscopic trip generation module has been developed that specifies trip generation individually for every household. This tool allows representing the heterogeneity in trip generation found in reality, and it adds flexibility if additional household attributes are added in the future.