Calibrating and Validating TRAF-NETSIM Model of Single-Point Urban Interchange

Abstract

A model of a single-point urban interchange (SPUI) was calibrated and validated using the traffic simulation program (TRAF-NETSIM). The model was calibrated on the basis of field observations at several existing SPUIs, and the model was validated on the basis of measures of effectiveness at a prototype interchange. Statistical analyses of several parameters were performed to determine confidence intervals and decile distributions and to compare values and distributions with defaults provided in TRAF-NETSIM. Other parameters were verified by informal field observations at the prototype interchange. The validation of the model demonstrated that TRAF-NETSIM can adequately represent traffic operations at a SPUI. Observations regarding the SPUI will provide additional insight into SPUI traffic operational characteristics. The methodology used to calibrate and validate the model of the SPUI should also be applicable to other modeling applications, ensuring a realistic and accurate representation of traffic operational conditions in a transportation system.

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