Field Evaluation of Detection-Control System [Tech Brief]

Federal Highway Administration2014PDFBriefUnited States. Department of Transportation. Federal Highway Administration. Turner-Fairbank Highway Research CenterUnited States. Federal Highway Administration. Office of Research, Development, and TechnologyTurner-Fairbank Highway Research CenterUnited States. Federal Highway AdministrationUnited StatesDilemma zoneField studiesHighway safetySignalized intersectionsTraffic signal controllersVehicle detectorsHigh speed intersectionsHighwaysOperations and Traffic ManagementI73: Traffic ControlFHWA-HRT-14-082High-speed signalized intersections present unique challenges to improving highway safety. Techniques for achieving safety often have an adverse effect on efficiency, and techniques for achieving efficiency sometimes have an adverse effect on safety. Bonneson et al. developed an alternative dilemma zone detection-control system (D-CS), which overcomes the limitations of traditional multiple advance-detector systems. The new system intelligently forecasts the best time to end the signal phase based on consideration of vehicle presence in the dilemma zone, vehicle type (i.e., truck or car), and the presence of vehicles waiting for a conflicting phase. This TechBrief is a technical summary of the Federal Highway Administration report of the same title (FHWA-HRT-14-058), which had the following objectives: (1) Verify the D-CS design objectives through rigorous field instrumentation\u2014at the moment of signal change from green to yellow, no truck shall be in the dilemma zone, and no more than one passenger car shall be in the dilemma zone; (2) Quantify the effectiveness of D-CS in improving safety and reducing dilemma-zone-related crashes and red-light violations at rural, high-speed, signalized intersections; and (3) Identify the upper limit of traffic conditions under which the D-CS can operate safely and effectively.95