Abstract: The present invention extends to methods, systems, and computer program products for monitoring signalized traffic flow. A processor in a sensor system or traffic controller interface estimates the time-of-arrival and other traffic flow estimates of one or more vehicles to an intersection stop bar, while the vehicles are within a continuous range of one or more transducers view of the sensor system. A level of efficiency and safety within the signalized traffic flow is estimated by the sensor system based upon one or more of the estimated time-of-arrival and other flow variables estimates and then communicated to the control unit of the traffic signal system. Other flow estimates for each vehicle include but are not limited to: position relative to the stop bar, lane position, velocity, acceleration, time headway and classification.

Abstract: The present invention extends to configuring detection zones in a traffic monitoring system and to association of detection zones with corresponding traffic signal phases. One or more sensors detect targets within a roadway intersection. The sensors integrate acquired sensor data for the targets into track files. The track files are subsequently used to identify common target paths. A histogram is used to identify common target positions for stationary targets. From the common target positions and the common target paths detection zones are configured. Detection zones are associated with traffic signal phases so that specific detections can be created. Lane boundaries within the roadway intersection are inferred from the common target paths. Permanent stationary target locations are identified from the common target positions.

Abstract: A scalable networking protocol that allows multiple nodes to communicate via a multi-channel network medium is described. The networking protocol allows any node on the network to assign itself as the active network server. The active network server polls client nodes based on a lineup card. The lineup card includes a high priority queue for low-latency devices, and a low priority queue for devices that can tolerate higher latencies. Network information is sent on the channels as fragments. The protocol provides bad-channel detection and retransmission of fragments in a fragment-by-fragment basis. Support for streaming data or asynchronous data is provided by allocating time slots on the network and allowing two intelligent nodes to talk directly to each other during count-limited token sessions, as arbitrated by the active network server.

Abstract: The present invention extends to methods, systems, and computer program products for monitoring signalized traffic flow. A processor in a sensor system or traffic controller interface estimates the time-of-arrival and other traffic flow estimates of one or more vehicles to an intersection stop bar, while the vehicles are within a continuous range of one or more transducers view of the sensor system. A level of efficiency and safety within the signalized traffic flow is estimated by the sensor system based upon one or more of the estimated time-of-arrival and other flow variables estimates and then communicated to the control unit of the traffic signal system. Other flow estimates for each vehicle include but are not limited to: position relative to the stop bar, lane position, velocity, acceleration, time headway and classification.