Safer signalized junction design and self‐optimizing control

摘要

AbstractThe UK Transport Research Laboratory has long had a Worldwide reputation for contributions to the field of traffic signal control, especially as originators of the TRANSYT and SCOOT signal coordination methods. This article describes some less widely known work. Accident risk at urban junctions and on road links between them is related to a wide variety of factors including: traffic and pedestrian flows, signal control parameters, geometry, and other layout features. Comprehensive studies have derived, and are continuing to derive, quantitative risk relationships for use in off‐line software. Those for individual signalized cross‐roads have already been incorporated in the TRL's program OSCADY to assist junction design. Now, an area‐wide safety model incorporating the CONTRAM traffic assignment program is being actively developed to provide a tool for evaluation of network traffic management schemes. For on‐line signal control at individual junctions, the MOVA system has been developed to provide a delay‐minimizing or capacity‐maximizing control logic as appropriate. ‘Before and after’ comparisons with the UK's previous fully vehicle‐actuated signal system are presented, including both delay a