Abstract: A system for controlling traffic for allowing passage of an emergency vehicle through an intersection controlled by traffic signals includes an intersection module for transmitting signals for preempting the traffic signals and one or more circuit cards coupled to the intersection module. Each expansion card includes a plurality of contact closures for outputting one or more of the signals for preempting the traffic signals. The intersection module selects an expansion card based on a type of output desired, and further selects one or more contact closures of the selected card for the desired output. The expansion cards allow preempt or vehicle outputs beyond the output that a single card can provide. According to another embodiment, the output expansion is achieved by emulating the communication interface between the intersection module and the traffic signal controller.

Abstract: An intersection controlled by an intersection controller receives trigger signals from on-coming emergency vehicles responding to an emergency call. The intersection controller initiates surveillance of the intersection via cameras installed at the intersection in response to a received trigger signal. The surveillance may begin immediately upon receipt of the trigger signal from an emergency vehicle, or may wait until the intersection controller determines that the signaling emergency vehicle is in the field of view of the cameras at the intersection. Portions of the captured images are tagged by the intersection controller based on tag signals transmitted by the vehicle or based on detected traffic patterns that indicate a potential traffic violation. The captured images are downloaded to a processing facility that analyzes the images and automatically issues citations for captured traffic violations.