RAMP METERS ON TRIAL : EVIDENCE FROM THE TWIN CITIES RAMP METERS SHUT-OFF

Ramp meters in the Twin Cities were turned off for 8 weeks in the Fall of 2000. This paper analyzes the results with and without ramp metering for two representative freeway, US 169 Northbound and I-94 eastbound during the afternoon peak period. Five performance measures: Accessibility, Mobility, Equity, Productivity and Consumer Surplus are compared. It is found that ramp meters are particularly helpful for long trips relative to short trips. On Route 169, trips more than 3 exits in length benefit, while those shorter are hurt by ramp meters. Ramp metering, while generally beneficial to freeway segments, may not improve trip travel times (including ramp delays). The results are mixed, suggesting a more refined ramp control algorithm which explicitly considers ramp delay is in order