Knowledge Resources

The City of Richmond installed a 4.7 million dollar advanced signal system at 262 signalized intersections and evaluated its impact on the central business district (CBD). The system was designed to coordination signal timing on four routes having independent signal timing plans. Timing was optimized using a system event schedule and the TRANSYT-7F signal timing optimization program. The timing plans were implemented using a central computer system and subsequently fine tuned based on input from drivers who compared traffic flow, signal phasing, splits, and offsets to platoon progression diagrams for each route. Field data were collected during peak periods using a test vehicle equipped with an automatic data collection system to record travel times, delays, stops, emissions, and fuel consumption before and after system deployment.

A series of runs performed on representative test sections on each route indicated that fuel consumption decreased 10 to 12 percent and emissions decreased 5 to 22 percent.