Reducing Highway Congestion: An Empirical Approach

The California Freeway Performance Measurement System (PeMS) database stores real-time data from 26,000 loopdetectors. PeMS extracts useful information from these data and displays it in graphical or tabular form. The data provide an unparalled opportunity to assess highway performance and discover ways to improve highway management. The paper illustrates this opportunity by suggesting approaches to reduce congestion. The approaches range from bottleneck identification and effective ramp metering to questioning the current operation of high-occupancy vehicle or carpool lanes.