THE EFFECTS OF THE ALL-RED CLEARANCE INTERVAL ON INTERSECTION ACCIDENT RATES IN INDIANA. FINAL REPORT

The research reported is an evaluation of all-red clearance intervals as the second phase of a project involving traffic signal operation. The first phase of the project dealt with leading versus lagging left turn signal phasing. The study analyzed both the short-term and long-term effects of all-red interval on accident rates in Indiana using accident records for the years 1981 to 1987. The results contradict those of previous studies. Statistical tests indicated that all-red clearance intervals did not cause a reduction in accident rates at the intersections studied in Indiana.