2 Technical Memorandum on Calibration / Validation of Traffic Microsimulation Models Prepared for Orange County Transportation Authority

Traffic simulation models have been increasingly utilized for the evaluation of traffic control systems and the prediction of future traffic conditions. Recent enhancements in computational capability have led to the development of high fidelity microscopic simulation models and this has accelerated their application in traffic engineering and, increasingly, in transportation planning. Microscopic simulation models, however, have very complex data requirements and numerous model parameters. Although most microscopic simulation programs provide data input guidelines and default model parameters, these models nevertheless need to be calibrated for the specific study area and the intended applications. The purpose of this memorandum is to provide some guidelines for appropriate use of microscopic simulation models. The specific approach is to discuss general issues in model calibration and validation from the perspective of global model parameters as well as from the perspective of location-specific direct adjustments of input data. These two perspectives can each critically influence the performance of the simulation model and the resulting validation exercise. Key issues addressed in this memorandum include overall model calibration/validation procedures. Discussion of specific model parameters to be calibrated, calibration methods, and model validation guidelines. A subsequent report will provide an application of selected calibration/validation techniques as part of a Paramics case study for the I-5/SR-55 interchange.