Project title: Improve current design of video imaging detection systems used for dilemma zone protection

459789117Technical report; Sept. 2006-Aug. 2008.PDFTech ReportFHWA/TX-09/0-5774-1Project 0-5774Video imaging detectorsDilemma zoneTraffic flowTraffic surveysTexasTexas Transportation InstituteMiddleton, DanPark, Eun SugLongmire, RyanCharara, HassanTexas Transportation InstituteTexas. Dept. of TransportationUnited States. Federal Highway AdministrationNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic Control DevicesNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic FlowNTL-PLANNING AND POLICY-SurveysUS Transportation CollectionThe use of video imaging vehicle detection systems (VIVDS) at signalized intersections in Texas hasincreased significantly due primarily to safety issues and costs. Installing non-intrusive detectors atintersections is almost always safer than installing inductive loops due to greater separation betweenpassing motorists and field crews installing the detectors. Other factors that have contributed to theincreased usage of VIVDS include the flexibility offered in terms of adjusting detection zones (e.g., withlane reassignments), the ability to send an image of the traffic stream to a traffic operations center, andno damage to the pavement structure as with inductive loops. Despite these advantages, there aresituations where VIVDS need further research to ensure safe operations. The objective of this research isto determine how well the current video imaging systems deployed by the Texas Department ofTransportation (TxDOT) provide dilemma zone protection at high-speed signalized intersections.Findings of this research indicate that VIVDS is better suited for stop line detection than dilemma zonedetection. It will usually require two cameras and dedicated upstream poles to ensure adequateperformance at speeds of 50 mph or higher. VIVDS has some inherent weaknesses that increase thenumber of max-outs and minor street delays compared to point detectors