PHASE TWO SIMULATION MODELING AND EXPERIENCE Sample Clauses

PHASE TWO SIMULATION MODELING AND EXPERIENCE. 7.3.1 Modeling the SR 99 Corridor The SR 99 section between 238th Street SW and 164th Street SW was modeled to simulate the Phase Two test corridor. The VISSIM model was configured by using the actual layout of the corridor and traffic control parameters. Field-observed traffic volumes, transit ridership estimates, and vehicle occupancy data were used to calibrate the model. The simulation software VISSIM provides a flexible and powerful platform for user-specific development. The emulated NEMA controller provided by VISSIM can properly function as a standard NEMA controller to satisfy the requirements of actuated signal control and basic TSP operations. However, the traffic controllers on this corridor were Naztec, which provide some different TSP functions than those provided by the NEMA controller. Therefore, an external controller was established for each intersection by using the vehicle actuated programming (VAP) language. The control logic and transit priority strategies of the Phase Two test intersections could be implemented by using the VAP programming language. Thus, a total of 13 external VAP controllers were developed, one for each intersection, for the SR 99 test corridor. Control parameters and TSP strategies were extracted from the real control system settings and applied to the calibration of the simulation models. The details of the calibration process are described below.