Since the late 1960's traffic engineers have been utilizing the power of computers to improve the flow of traffic on their streets. As a result, a large number of computerized traffic signal systems have been installed over the last 20 years and are in fact continuing to be installed. Many of these systems are nearing the end of their life expectancy and need to be rehabilitated to continue their useful operation. A municipality may decide to replace its current system for reasons other than for life expectancy. Such reasons may include the desire to improve traffic operation to provide user enhancements, or to incorporate modern technology. Current users of computerized traffic control systems wanting to modernize their systems are faced with the problem of what to do. The industry has a history of instability and lack of long term support. In addition, there is the question of what parts of the existing system can be retained in any new system. This paper reports on the experience of 3 municipalities who are currently replacing/upgrading their existing signal systems. The municipalities involved are the City of Lincoln, Nebraska; the City of Minneapolis and Metropolitan Toronto.
Abstract