Distributed Microcomputer-Based Control of Multiple Signalized Traffic Intersections

Microcomputer-based control of a signalized urban multi-intersection system is considered. A hierarchical control configuration involving a central controller, which utilizes also a mainframe computer, regional controllers and local controllers at each intersection, is proposed. An optimization procedure, utilizing the mixed-integer programming approach, and maximizing the green light band, is implemented by the central controller for all intersections. The mixed-integer programming algorithm is run on a CDC CYBER 170/720 computer. A complete hardware design of the controllers at all levels, utilizing Intel 8085 (for the central controller) and Intel 8051 (for the regional and local controllers) has been performed. A software package for all controllers has been prepared. The whole system has been simulated on the CYBER 170 and on an Intel MDS-251 Development System.