Synthesized Through-Trip Models for Small and Medium Urban Areas

The estimation of through trips is an important component of travel demand models for small and medium communities, which are home to about 75% of U.S. residents. Many of these communities have sizable through trips and may not have resources to conduct external surveys to develop through-trip tables. The current through-trip models for communities with populations of less than 50,000 are updated, and a new, two-phase through-trip model for medium areas with populations between 50,000 and 200,000 is developed. In Phase 1, one regression model estimates the percentage of through-trip ends at each external station. In Phase 2, two regression models estimate the distribution of the through-trip ends among external stations for small and medium communities. The models have acceptable goodness of fit and validated model assumptions. The introduction of new economic and geographic factors improves the model's predictive power compared to that of previous models. The model is straightforward and efficient compared to expensive external surveys. It can be embedded into the standard travel demand forecasting process. It appears transferable to other small and medium urban areas.