Improving Minneapolis/St. Paul's Ramp Metering System for Smoother Traffic Flow

To streamline traffic flow and reduce backups on Twin Cities highways, Mn/DOT engineers researched ways to improve the algorithm they use to estimate queue size on entrance ramps and calculate minimum rates for releasing cars from ramps to highways. More than 20 parameters were tested through computer simulations. The new optimized algorithm and ramp-monitoring system increases average speed and reduces travel time and energy consumption.