The results of an ongoing advance AccuScan 1000 detection study have demonstrated that advance detection is a proficient solution for reducing incidents at dilemma zones and intersections – red-light violations and crash frequencies – while also reducing vehicle delays and stops. Moreover, the benefits and cost effectiveness increase, as vehicle detection is located further from the intersection.
Supporting the advance detection research findings, the FHWA Traffic Detector Handbook and Arterial Management Program provide a roadmap for agencies and MPOs to effectively address both safety and capacity of arterials through an advance detection strategy. Furthermore, the FHWA Traffic Signal Manual details the detection design for high-speed approaches taking into careful consideration the location for advance detection relative to posted speed. Ideally, detection should be located approximately 5 to 5.5 seconds of travel time with 3 to 5 detectors to provide safe termination of the high speed approach phase. Unfortunately, in many cases, the costs, construction, maintenance, and traffic disruption associated with installing arrays of inductive loops can be prohibitive.