Abstract: A method and system for synchronization of detection loops in a multilane environment. A plurality of loop sensors are arranged in a plurality of lanes such that loop sensors in adjacent lanes are mutually contiguous. A simultaneous synchronization signal is sent to each of the plurality of loop detector controllers, where each loop detector controller is in communication with a loop sensor. The signal causes a scheduling of sampling periods for each loop sensor, such that the sampling period of each loop sensor does not overlap with that of a contiguous loop in an adjacent lane.

Abstract: A method and system for synchronization of detection loops in a multilane environment. A plurality of loop sensors are arranged in a plurality of lanes such that loop sensors in adjacent lanes are mutually contiguous. A simultaneous synchronization signal is sent to each of the plurality of loop detector controllers, where each loop detector controller is in communication with a loop sensor. The signal causes a scheduling of sampling periods for each loop sensor, such that the sampling period of each loop sensor does not overlap with that of a contiguous loop in an adjacent lane.

Abstract: A method and apparatus for monitoring for Red Fail faults in a traffic signal control system. Traffic control signals generated by a traffic control unit are grouped into channels. Certain channels are specified for Red Fail testing in which all lights in a given channel are inactive at the same time. Channels which are not specified are not subject to Red Fail testing, but other conflict testing can still be performed on these unselected channels.

Abstract: A method and system for synchronization of detection loops in a multilane environment. A plurality of loop sensors are arranged in a plurality of lanes such that loop sensors in adjacent lanes are mutually contiguous. A simultaneous synchronization signal is sent to each of the plurality of loop detector controllers, where each loop detector controller is in communication with a loop sensor. The signal causes a scheduling of sampling periods for each loop sensor, such that the sampling period of each loop sensor does not overlap with that of a contiguous loop in an adjacent lane.

Abstract: A vehicle detector system having a number of individual vehicle detectors each capable of sampling a plurality of vehicle loops in mutual synchronization. One detector operates as a master detector for synchronization purposes; the other detectors are operated as slave detectors. The system can be configured for series or parallel synchronous operation. The system is particularly advantageous in installations requiring a large number of closely spaced vehicle loops each operated by a detector set to high sensitivity.

Abstract: A method and apparatus for monitoring for Red Fail faults in a traffic signal control system. Traffic control signals generated by a traffic control unit are grouped into channels. A parent-child relationship is established between some channels. When testing for a Red Fail fault, the control signals in both the parent channel and the child channel are examined. A Red Fail fault will occur only if all the control signals examined in both the parent and the child channel are inactive. The control signals examined in the child channel can be limited to the Green and Walk signals; or may include the Yellow signals.

Abstract: A method and apparatus for automatically testing the integrity of an inductive loop in a vehicle detector system. A check loop is placed adjacent each inductive loop in a multi-channel vehicle detector system. Each check loop is periodically activated by the vehicle detector to simulate a vehicle load on the associated inductive loop. Samples representing loop inductance at different activation periods are compared with a standard. When the result exceeds the standard, the inductive loop is subjected to additional sample testing with decreasing time intervals between sampling. After a number of additional samples exceed the standard, the inductive loop is deemed failed.

Abstract: A m thod and apparatus for monitoring for Red Fail faults in a traffic signal control system. Traffic control signals generated by a traffic control unit are grouped into channels. Certain channels are specified for Red Fail testing in which all lights in a given channel are inactive at the same time. Channels which are not specified are not subject to Red Fail testing, but other conflict testing can still be performed on these unselected channels.

Abstract: A malfunction management method and apparatus for monitoring the levels of D.C. voltage supply signals from power supplies used to power associated traffic control equipment. A D.C. voltage from each power supply is checked against a reference threshold value in the malfunction management unit. If either voltage drops below the threshold value for a minimum time period, a fault signal is generated and the operation of the traffic control equipment is overridden. The threshold value used to test the D.C. voltage levels is selectable between the same level for all inputs or different levels for different inputs.

Abstract: A method and apparatus for monitoring for Red Fail faults in a traffic signal control system. Traffic control signals generated by a traffic control unit are grouped into channels. A parent-child relationship is established between some channels. When testing for a Red Fail fault, the control signals in both the parent channel and the child channel are examined. A Red Fail fault will occur only if all the control signals examined in both the parent and the child channel are inactive. The control signals examined in the child channel can be limited to the Green and Walk signals; or may include the Yellow signals.

Abstract: A vehicle detector system having a number of individual vehicle detectors each capable of sampling a plurality of vehicle loops in mutual synchronization. One detector operates as a master detector for synchronization purposes; the other detectors are operated as slave detectors. The system can be configured for series or parallel synchronous operation. The system is particularly advantageous in installations requiring a large number of closely spaced vehicle loops each operated by a detector set to high sensitivity.

Abstract: A malfunction management method and apparatus for monitoring for conflicts between pedestrian advisory sign control signals and vehicle Ian signal head control signals generated by a traffic control unit. Continuously activated (solid) control signals for pedestrian advisory signs and vehicle lane signal heads are monitored for conflicts between WALK pedestrian signals and GREEN and YELLOW vehicle signals for vehicle lanes potentially conflicting with the pedestrian walk way. Flashing DON'T WALK pedestrian signals and continuously activated Green and YELLOW vehicle signals for potentially conflicting vehicle lanes are also monitored for conflicts. A display indicates which input signal channels are enabled for monitoring in the flashing DON'T WALK mode.

Abstract: A method and apparatus for automatically testing the integrity of an inductive loop in a vehicle detector system. A check loop is placed adjacent each inductive loop in a multi-channel vehicle detector system. Each check loop is periodically activated by the vehicle detector to simulate a vehicle load on the associated inductive loop. Samples representing loop inductance at different activation periods are compared with a standard. When the result exceeds the standard, the inductive loop is subjected to additional sample testing with decreasing time intervals between sampling. After a number of additional samples exceed the standard, the inductive loop is deemed failed.