Intro to Calibration (and Validation)

TDMs typically consist of many submodels, e.g. a TDM might include a Trip Generation Model. Each of these submodels are developed separately from a suitable source of estimation data ( for example HouseHold Travel Surveys (HHTS) This estimation data can also be used to test how well these submodels work together. For example, the results of the joint operation of separately developed Trip Generation, Trip Distribution and Mode Choice Models should be consistent with the trip table of demand that is reported in those HHTSs. This process is typically called Model Calibration.

In addition to ensuring that the various model subcomponents work together as intended, the results can also be checked against a source of independent data that was NOT use to develop the TDM. This processes is typically called Model Validation.

The topics presented are intended to provide a general overview into the Calibration and Validation of TDMs.