Enhanced THOREAU traffic simulation for intelligent transportation systems (ITS)

Traffic and Highway Objects for Research, Analysis and Understanding (THOREAU) is an object-oriented microscopic and mesoscopic traffic simulation tool for traffic engineers. It emphasizes the simulation of advanced traveler information systems (ATIS) and advanced traffic management systems (ATMS) as components of intelligent transportation systems (ITS). This paper describes recent enhancements to THOREAU in the area of ATMS, namely the microsimulation of actuated signals and corridor-wide signal optimization in conjunction with route guidance and incident management. There are strong coupling effects among various trip time control parameters including signal cycle times, green wave offsets, and ATMS control strategies. Using sample urban traffic networks, the impacts of actuated signal controllers, the adaptive Webster-Cobbe (1966) algorithm for isolated intersection, traffic detector placement strategies and coordinated corridor-wide optimization can be quantified. Consequently, traffic engineers may use THOREAU to explore alternative ITS technologies or architectures for optimal signal control and to validate network performance estimates obtained through analytic or rule-of-thumb approaches