Bellevue, Washington, a city of 80,000 population with 100 traffic signals, has recently completed installation of a "1.5 generation" Urban Traffic Control System (UTCS) based traffic control system. The "1.5 generation" UTCS control system includes a timing plan generation program, FORCAST, that can load and implement automatically generated plans into the traffic control system with simple operator commands. With the help of the FORCAST software and system detectors installed city wide, timing plans can be updated and maintained regularly in response to changes in traffic demands with little operator effort. The city has installed in the central business district a fibre optic based closed circuit television (CCTV) system. The system allows real time monitoring of traffic conditions along critical sections of four major arterials. The CCTV system is connected to a time lapse video recorder which can be used to record traffic flows during unattended weekends or holiday periods. Remote communication with the traffic control system is possible using a cellular phone and a laptop computer with an internal modem. This is used to verify operation of the system and to make optimizing timing plan changes during travel time and delay studies. This paper covers the optimization of a "1.5 generation" UTCS based traffic signal system and the use of the CCTV system and the cellular phone in this process. It also describes the use of the on-line database and on-line traffic signal pattern development program called FORCAST.
Abstract