Application of Distributed Traffic Simulation to Evaluate Traffic Signal Controller Algorithms

Traffic simulation, interfaced with traffic controller algorithms, can be used to evaluate traffic operations and traffic control benefits in a laboratory environment. This virtual "hardware-in-the-loop" environment, when residing in different computers, is referred to as distributed traffic simulation. To facilitate this type of simulation, a new Application Programming Interface (API) was developed to interface CORSIM (CORridor SIMulation). The API was implemented through the Distributed Component Object Model (DCOM), a client/server environment developed by Microsoft Corporation. An emergency preemption vehicle (an ambulance or a fire truck) experiment was designed to test the API. A sample cases were run successfully in real time on a TCP/IP network without any program execution delays. The test case shows that the new API could be interfaced with different traffic control applications with minor source code changes. This DCOM API will be useful to traffic simulation researchers, software developers, and traffic engineers. The results from this experiment will also be useful to CORSIM developers as a reference for future enhancement.