Communication bandwidth requirements for urban traffic control systems are relatively low. However, the cost of communications represents a disproportionate percentage of the total life cycle cost of providing urban traffic control. This is due to the large investment in infrastructure required for cable and conduit installation in urban areas and the lease costs which are proported to represent these costs. The proprietary nature of traffic signal controllers communication protocols is one of the barriers to the implementation of "open" traffic control systems and ongoing competitive procurement of traffic signal controllers. The region of York, north of Metropolitan Toronto in Ontario, Canada faced and overcame these problems through the development and implementation of an "open" Centralized Traffic Control Systems (CTCS). The CTCS communicates with eight models of traffic field controllers, from three manufacturers over a combination of leased communication circuits and spread spectrum radio links.
Abstract