Development of a travel demand model for transborder commuter activity

The southern US border is a region of great economic activity. Key port-of-entry locations on this region usually link twin cities and thus have become facilities were substantial traffic cross on a daily basis. Seeking to improve the forecast of such flows, the present research effort focused on development of a new procedure for disaggregate travel modeling of persons in a bi-national conurbation. This procedure steps away from the conventional approach of studying separately each side of the international boundary, and thus from modeling ports-of-entry through the simplistic use of external zones. The new approach extends the model boundaries beyond international limits, covering the urban areas on both sides, and thus joining the two systems through the ports-of-entry, which eliminates the need for external zones at these locations. Developing and validating an international crossing model with mode choice capability is nevertheless more complex than simply joining together two existing travel demand models (TDMs). These issues have been considered herein and an initial set of modeling methodologies have been researched and tested with encouraging findings. The 9/11 events complicated the border processing element of the commuter trip, however, as the study will show, the model produced reasonable estimations for 2005, even when originally calibrated with pre-9/11 data. This study thus represents an unprecedented effort for any border urban area in the United States or Mexico.