Chapter 1 REAL TIME SIMULATION OF TRAFFICDEMAND - SUPPLY INTERACTIONSWITHINDYNAMITMoshe

DynaMIT is a simulation-based real-time system designed to estimate the current state of a transportation network, predict future traac conditions , and provide consistent and unbiased information to travelers. To perform these tasks, eecient simulators have been designed to explicitly capture the interactions between transportation demand and supply. The demand reeects both the OD ow patterns and the combination of all the individual decisions of travelers while the supply reeects the transportation network in terms of infrastructure, traac ow and traac control. This paper describes the design and speciication of these simulators, and discusses their interactions. 1. INTRODUCTION The main role of Dynamic Traac Management Systems (DTMS) is to improve general traac conditions using advanced technologies, managed by real-time intelligent software systems. There are two important functions of such systems. In the context of the economic interpretation of transportation, one of them aaects transportation supply, while the other innuences transportation demand. Control systems, often called Advanced Traac Management Systems (ATMS), impose restrictions and constraints on traac ows. These systems include traac lights (based on xed timing or on pro-active rules), ramp metering, speed limit signs ((xed or variable) and lane use signs. In general, driving laws force drivers to comply with these systems. By