Abstract: Disclosed approaches for selecting a travel route involve considering phase interruptibility of traffic signals on alternative routes. Multiple alternative routes are determined in response to a request for a route. Information describing each route specifies a set of road segments, a set of intersections, and estimated travel times on the road segments. For each road segment that connects to an intersection having a phase-interruptible traffic signal, the estimated travel time on the segment is reduced based on a correction factor associated with the intersection. Estimated travel times on the alternative routes are determined based on the reduced estimated travel times on the segments. One or more of the alternative routes are displayed, including a visual indication of the route having the least estimated travel time.

Abstract: Controlling traffic signal preemption includes inputting to a conditional preemption circuit, values of incident parameters that include at least a vehicle unit identifier of a vehicle unit and an incident priority that describes an incident. The conditional preemption circuit determines a vehicle class based on one or more of the plurality of incident parameters. In response to a preemption request communicated from the vehicle unit, the conditional preemption circuit determines whether or not the vehicle unit qualifies for preemption at one or more intersections based at least on the vehicle class, location of the vehicle, and heading of the vehicle unit specified in the preemption request. Phase selection signals are communicated to traffic signal control circuitry at the one or more intersections in response to determining that the vehicle unit qualifies for preemption at the one or more intersections.

Abstract: According to the disclosed approaches, a server system receives vehicle messages having information transmitted from vehicle processors. Each vehicle message specifies published geographical coordinates that indicate a geographical location of a vehicle. For each vehicle message, the server system determines one or more virtual phase selectors associated with the published geographical coordinates; determines whether each virtual phase selector is active or inactive; starts execution of each virtual phase selector determined to be in inactive; and communicates the vehicle message to the one or more virtual phase selectors. Each virtual phase selector determines traffic signal control data based on the vehicle message and transmits the traffic signal control data to a traffic signal controller associated with the virtual phase selector.

Abstract: According to the disclosed approaches, a first processor receives location messages from second processors. Each location message specifies published geographical coordinates that indicate a geographical location, and the published geographical coordinates are a version of actual geographical coordinates truncated from a first level of precision to a second level of precision. The first processor accesses subscriptions to location topics in response to the location messages. Each location topic specifies in the second level of precision, subscribed-to geographical coordinates of a location. The first processor determines whether or not the published geographical coordinates match any of the subscribed-to geographical coordinates. Non-matching location messages are discarded, and matching location messages are transmitted to one or more third processors identified by the subscriptions.

Abstract: Controlling traffic signal preemption includes inputting to a conditional preemption circuit, values of a plurality of incident parameters that include at least a vehicle unit identifier of a vehicle unit and an incident priority that describes an incident. The conditional preemption circuit determines a preemption mode for a vehicle associated with the vehicle unit identifier based on one or more of the plurality of incident parameters. The preemption mode is one of a first mode or a second mode. Traffic signal preemption is enabled for the vehicle unit in response to the conditional preemption circuit determining the first mode. Traffic signal preemption is disabled for the vehicle unit in response to the conditional preemption circuit determining the second mode.

Abstract: Approaches are disclosed for timing the submission of transit signal priority (TSP) requests. A phase selector receives TSP information of a vehicle at a current time, and the phase selector determines an estimated time of arrival (ETA) of the vehicle at an intersection having a traffic signal controlled by an intersection controller. The phase selector determines the arrival phase of the traffic signal at the ETA, along with a phase-relative arrival time of the ETA. The phase selector determines a time to issue the TSP request based on the phase-relative arrival time, and issues the TSP request to the intersection controller at the determined time.

Abstract: The disclosure describes a device for configuring an infrared (IR) emitter. The device includes a support structure and a microprocessor attached to the support structure. An interface circuit is also attached to the support structure and is configured to provide communications between the microprocessor and a portable computing device. A memory, which is attached to the support structure, is coupled to the microprocessor and is configured with instructions. Execution of the instructions by the microprocessor cause the microprocessor to communicate with an application executing on the portable computing device and initiate transmission of configuration data received from the application to the IR emitter. A transmitter is attached to the support structure and is coupled to the microprocessor. The transmitter is configured to transmit the configuration data to the IR emitter.

Abstract: Approaches for managing transit vehicle schedules. The method includes determining a current location and current heading of a transit vehicle by a global positioning system (GPS) module aboard the transit vehicle and communicating the current location and current heading to a computer processor. The computer processor determines a current time and current day, and a trip schedule is selected from a plurality of trip schedules in a database. The selected trip schedule has attributes consistent with the current location, current heading, current time, and current day. The method determines whether the transit vehicle is ahead of the selected trip schedule or behind the selected trip schedule. An output signal indicates whether the transit vehicle is ahead of or behind schedule.

Abstract: Approaches for prioritizing multiple candidates for preemption of a traffic signal phase at an intersection are disclosed. Light signals transmitted from light-signaling vehicles approaching an intersection encode priority codes using a first set of values. Radio signals from radio-signaling vehicles approaching the intersection encode priority codes using a second set of values. A set of preemption candidates is determined from the light and radio signals, as well as from network-based requests, and a respective relative priority of each preemption candidate based on the priority code of each preemption candidate is determined. A request output for preemption of the traffic signal phase for a preemption candidate having a highest priority.

Abstract: Approaches for classifying vehicles include generating a signal waveform from a signal in a single inductive loop generated by a passing vehicle. The signal waveform is compared to a first plurality of model waveforms. Each model waveform is associated with a respective class of vehicle. A first model waveform of the first plurality of model waveforms that matches the signal waveform is determined, and data indicating the respective class of vehicle associated with the first model waveform is output.

Abstract: The disclosed approaches for processing traffic signal priority requests include receiving traffic signal priority requests from a vehicle. The number of stopped vehicles at the intersection and on an approach to the intersection is determined in response to receiving each priority request. An activation threshold is computed as a function of an estimated-time-of-arrival (ETA) threshold and the number of stopped vehicles. A vehicle ETA of the vehicle at the intersection is determined in response to each priority request. In response to the vehicle ETA being less than the activation threshold, the priority request is submitted for preemption service processing at the intersection. In response to the vehicle ETA being greater than the activation threshold, submission of the priority request is bypassed for preemption service processing at the intersection.

Abstract: Approaches for managing transit signal priority (TSP) requests are disclosed. The arrival of a first transit vehicle at a transit stop is detected, and a first value indicative of an actual arrival time is stored in a memory in response to the arrival of the first transit vehicle at the transit stop. A processor determines from the first value whether or not the actual arrival time of the first transit vehicle satisfies a scheduling parameter. In response to the actual arrival time of the first transit vehicle not satisfying the scheduling parameter, a priority request device is enabled to make TSP requests. In response to the actual arrival time of the first transit vehicle satisfying the scheduling parameter, the priority request device is disabled from making TSP requests.

Abstract: Approaches for issuing preemption requests. The boundaries of a geo-window are repeatedly determined based on locations and headings of a vehicle as the vehicle is traveling along a roadway. The methods and systems determine whether or not any one of a plurality of intersections is located within the boundaries of the geo-window in response to changed boundaries of the geo-window. In response to determining that one of the plurality of intersections is located within the boundaries of the geo-window, a preemption request is transmitted from the vehicle to an intersection controller at the one of the plurality of intersections.

Abstract: A priority control unit is provided for use with light-based and GPS-based traffic control priority systems. The priority control unit includes a light emitter subsystem that is configured to emit pulses of light. The pulses of light encode a priority request for activating preemption of a traffic signal by a light-based traffic control priority system. The priority control unit also includes a GPS-based subsystem that is configured to transmit a priority request by radio waves. The priority request from the GPS-based subsystem is for activating preemption of a traffic signal by a GPS-based traffic control priority system. A switch is coupled to the light emitter subsystem and to the GPS-based subsystem. The switch simultaneously activates both the light emitter subsystem and the GPS-based subsystem for transmitting priority requests in response to user control. In another embodiment, the priority control unit further includes a broadcast based subsystem for transmitting priority requests.

Abstract: Approaches for monitoring traffic signal preemption at one or more intersections. According to one embodiment, a road map that includes a plurality of roads and intersections is displayed with a computer system. Preemption data periodically received by the computer system from at least one preemption controller at a respective intersection is used to update the road map. In response to the preemption data, the road map is updated to include a traffic signal icon at the respective intersection and a vehicle icon at a location on the map corresponding to a location of a vehicle transmitting a preemption request as indicated by the preemption data.

Abstract: Controlling a traffic signal phase at one or more intersections. A control system at an intersection is configured to operate in one of a first mode or a second mode. While operating the controller in the first mode, in response to a transit priority signal received by the control system from a vehicle assigned transit priority, a green phase of the traffic signal is extended in favor of the vehicle assigned transit priority. While operating the control system in the second mode, in response to a transit priority signal received by the control system from the vehicle assigned transit priority, a current non-green phase of the traffic signal is preempted to a green phase in favor of the vehicle assigned transit priority.

Abstract: Management of traffic signal preemption control equipment. In one approach, logged preemption data is periodically read from each of a plurality of intersections having respective preemption controllers for preempting traffic signals at the intersections. The logged preemption data at an intersection describes operational states of the preemption controller and each vehicle control unit that submitted a preemption request at the intersection and data describing each individual preemption request. The logged preemption data read from the plurality of intersections are stored in a database. The database is monitored for data indicative of changes in operational status of the traffic signal preemption control equipment. In response to the data indicating a change in operational status, data descriptive of the change are output.

Abstract: Managing traffic signal preemption data accumulated at a plurality of intersections. In one approach a method includes reading the preemption data stored at each of the intersections. The preemption data includes for each preemption request an emitter code, and a date and a time the preemption request was submitted. The preemption data read from the intersections are stored in a database, and each emitter code is associated with a vehicle name in the database. Selected preemption data and associated vehicle names are read from the database in response to user input, and the selected preemption data and associated vehicle names are displayed. The database further stores data identifying the intersection from which the preemption data was read.

Abstract: Managing traffic signal preemption at a plurality of intersections. In one approach a security level code that specifies one of a plurality of security levels for at least one jurisdiction is input. The security level controls which emitter codes are allowed to preempt traffic signals at the intersections in the jurisdiction. A set of emitter codes for the plurality of intersections in the jurisdiction is determined in response to the security level code. The set of emitter codes is downloaded to a plurality of preemption controllers at the plurality of intersections in the jurisdiction. Each preemption controller accepts a preemption request only if the preemption request contains an emitter code indicated by the downloaded set of emitter codes as being allowed to preempt traffic signals at the intersections in the jurisdiction.

Abstract: Various approaches for activating a traffic control preemption system. A light bar includes a support structure and a plurality of LED modules individually mounted on the support structure. Each LED module includes a plurality of LED groups, and in at least one of the plurality of LED modules, at least one LED group in the module is an infrared (IR) LED group, and at least one LED group in the module is a visible light LED group. A controller is coupled to each module. The controller is configured to trigger an IR light pulse pattern at a first level of IR radiant power from the at least one IR LED group. The pulse pattern and first level of IR radiant power activate preemption in a traffic control preemption system.