Detroit, Michigan, United States
Detroit Freeway Corridor ITS Evaluation
Summary Information
ITS in the corridor consisted of internet-based pre-trip advanced traveler information systems (ATIS), highway advisory radio (HAR), ramp metering, and dynamic message signs (DMS). The performance of these systems was analyzed through a series of simulations that evaluated four alternatives:
- No-ITS.
- Ramp metering.
- Variable message signs.
- Existing-ITS (ATIS, HAR, ramp metering, and DMS).
The INTEGRATION simulation model was used to generate peak PM arterial and freeway corridor conditions for roughly 40,000 to 50,000 vehicles per hour during 80 different scenarios of impedance (varied weather, incident patterns, etc.). The model was calibrated using flow and speed data derived from field observations.
FINDINGS
Field data indicated that under typical peak hour conditions, freeway bias could not exist because average freeway travel speeds were higher than those on arterials. The lack of available data on freeway speeds during incidents precluded an analysis of freeway bias during incidents.
The simulation results demonstrated how existing ITS systems were beneficial to corridor capacity. Ramp metering was most effective at reducing congestion during major incidents, however, the study questioned its use in the absence of incidents or during minor incidents.