Model Validation
The primary goal in developing a regional travel demand model is to provide a means for making informed decisions regarding proposed transportation improvements. To that end, both model results, and the process used in developing the model, need to be sound and defensible. Consequently, substantial time and effort are invested in developing and validating a base year model to ensure its reliability.
Model validation is the process whereby the model's credibility is proven based on replicating observed conditions (e.g. traffic counts, vehicle miles of travel). Thus, model validation is an attempt to replicate travel for the year in which the field data (i.e., travel survey, network, and other data) are collected.