A VARIABLE-SEQUENCE MULTIPHASE PROGRESSION OPTIMIZATION PROGRAM

Abstract

A TRAFFIC SIGNAL PROGRESSION PROGRAM HAS BEEN DEVELOPED THAT MAXIMIZES PROGRESSION ALONG A FACILITY HAVING MULTIPHASE SIGNALS. THE MAIN STREET GREEN PHASE SEQUENCES OF LEFT TURNS FIRST, THROUGH MOVEMENTS FIRST, LEADING GREEN, AND LAGGING GREEN CAN BE EVALUATED AT EACH INTERSECTION. THE PROGRESSION PROGRAM CAN DETERMINE WHICH OF THE FOUR PHASE SEQUENCES PROVIDES MAXIMUM PROGRESSION. CONVENTIONAL TWO-PHASE SIGNAL OPERATION IS A SPECIAL CASE OF THE THROUGH-MOVEMENTS-FIRST SEQUENCE. THE COMPUTER PROGRAM, WRITTEN IN FORTRAN IV, CAN ALSO COMPUTE MOVEMENT DURATIONS AND PHASE SPLITS IF DESIRED THE PROGRESSION PROGRAM WAS ADAPTED FOR USE IN THE REAL-TIME CONTROL OF AN ARTERIAL PILOT CONTROL SYSTEM IN DALLAS. THE CONTROLLERS WERE MODIFIED TO PERMIT VARIABLE-PHASE SEQUENCE OPERATION. GOOD PROGRESSION WAS OBTAINED, AND NO APPARENT PROBLEMS HAVE OCCURRED DUE TO THE VARIABLE-PHASE SEQUENCING.