Citation

Tsiknas J, Legrand L. ITE J. 1989; 59(6): 17-19.

Copyright

(Copyright © 1989, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

A master traffic control system for 150 signals was implemented in the central business district of San Diego in 1984. The central system is controlled by a Perkin-Elmer model 3230 computer with two megabytes of memory driven by Enhanced Urban Traffic Control System (UTCS) software. A front-end communications processor is used to do actual second-by-second data transmission. Data between the central computer and the front-end communications processor are transferred in blocks via two 8-kilobyte buffers in the central processor. Details of the software, communications network, and intersection controllers are described. The trolley preemption for the two light rail transit lines is described. System costs are discussed, and future plans are noted.