The goal of trip generation is to predict the number of trips, by purpose, that are generated by and attracted to each zone in a study area. Trip generation is performed by relating the number or frequency of trips to the characteristics of the individuals, of the zone, and of the transportation network. The zone that contains the home end of home-based trips or the origin end of non-home-based trips is considered to have produced the trip, while the destination zone where an out-of-home activity will be undertaken is considered to have attracted the trip.
TransCAD Transportation Planning Software includes a variety of trip generation models to forecast trip productions and attractions on any level of geographic aggregation. Among the methods are cross-classification, regression, and discrete choice models. TransCAD provides methods for the application and estimation of trip generation models. Also included is a powerful method to produce synthetic populations consistent with demographic distributions. The outputs of the population synthesis may be used as inputs to both traditional travel demand models as well as more advanced Activity-Based Models (ABM).