ADOT CV Roadside Equipment - Connected Vehicle Roadside Equipment Functionality
Subsystem Description
'Connected Vehicle Roadside Equipment' (CV RSE) represents the Connected Vehicle roadside devices that are used to send messages to, and receive messages from, nearby vehicles using Dedicated Short Range Communications (DSRC) or other alternative wireless communications technologies. Communications with adjacent field equipment and back office centers that monitor and control the RSE are also supported. This device operates from a fixed position and may be permanently deployed or a portable device that is located temporarily in the vicinity of a traffic incident, road construction, or a special event. It includes a processor, data storage, and communications capabilities that support secure communications with passing vehicles, other field equipment, and centers.
Functional Object: RSE Automated Vehicle Operations
'RSE Automated Vehicle Operations' includes the field elements that monitor and control access to and egress from automated lanes. It monitors and coordinates automated vehicle operations within the lanes. These lanes support vehicles operating in platoons with short headways.
Functional Object: RSE Communications Relay
'RSE Communications Relay' provides message relay services that extend effective communications range to improve communications systems performance and robustness. It also supports safety applications such as wrong way vehicle detection and other applications where roadside communication of warnings beyond DSRC range are needed to compensate for high speeds or line of site/RF interference challenges.
Functional Object: RSE Device Management
'RSE Device Management' provides executive control and monitoring of the RSE hardware and installed software applications. It monitors the operational status of the hardware and other attached field devices and detects and reports fault conditions. A back office interface supports application installation, upgrade, and configuration as well as remote control of the operating mode and hardware configuration settings and initiation of remote diagnostics. A local interface is provided to field personnel for local monitoring and diagnostics, supporting field maintenance, repair, and replacement.
Functional Object: RSE Environmental Monitoring
'RSE Environmental Monitoring' collects environmental situation (probe) data from passing vehicles that are equipped with short range communications capability. The collected data includes current environmental conditions as measured by on–board sensors (e.g., ambient temperature and precipitation measures), current status of vehicle systems that can be used to infer environmental conditions (e.g., status of lights, wipers, ABS, and traction control systems), and emissions measures reported by the vehicle. The functional object collects the provided data, aggregates and filters the data based on provided configuration parameters, and sends the collected information back to a center for processing and distribution. This functional object may also process the collected data locally and issue short–term road weather advisories for the road segment using short range communications.
Functional Object: RSE Intersection Management
'RSE Intersection Management' uses short range communications to support connected vehicle applications that manage signalized intersections. It communicates with approaching vehicles and ITS infrastructure (e.g., the traffic signal controller) to enhance traffic signal operations. Coordination with the ITS infrastructure also supports conflict monitoring to ensure the RSE output and traffic signal control output are consistent and degrade in a fail safe manner.
Functional Object: RSE Position Correction Support
'RSE Position Correction Support' broadcasts differential positioning data to enable precise locations to be determined by passing vehicles, supporting Connected Vehicle applications that require highly accurate positioning. The differential positioning data may be calculated directly by a precisely located RSE that is operating as a reference station or received from an external reference station and relayed to passing vehicles.
Functional Object: RSE Queue Warning
'RSE Queue Warning' provides V2I communications to support queue warning systems. It monitors connected vehicles to identify and monitor queues in real–time and provides information to vehicles about upcoming queues, including downstream queues that are reported by the Traffic Management Center.
Functional Object: RSE Speed Management
'RSE Speed Management' provides infrastructure information including road grade, roadway geometry, road weather information, and current speed limits to assist vehicles in maintaining safe speeds and headways. It also provides speed recommendations to vehicles based on current conditions and overall speed limits and strategies established by the back office.
Functional Object: RSE Support Services
'RSE Support Services' provides foundational functions that support data collection, management, location reference, timing, and data distribution. It coordinates with Support subsystems to maintain necessary registrations with respect to location and scope. It maintains precise location and time information to support other services.
Functional Object: RSE Traffic Monitoring
'RSE Traffic Monitoring' monitors the basic safety messages that are shared between connected vehicles and distills this data into traffic flow measures that can be used to manage the network in combination with or in lieu of traffic data collected by infrastructure–based sensors. As connected vehicle penetration rates increase, the measures provided by this application can expand beyond vehicle speeds that are directly reported by vehicles to include estimated volume, occupancy, and other measures. This object also supports incident detection by monitoring for changes in speed and vehicle control events that indicate a potential incident.
Functional Object: RSE Traveler Information Communications
'RSE Traveler Information Communications' includes field elements that distribute information to vehicles for in–vehicle display. The information may be provided by a center (e.g., variable information on traffic and road conditions in the vicinity of the field equipment) or it may be determined and output locally (e.g., static sign information and signal phase and timing information). This includes the interface to the center or field equipment that controls the information distribution and the short range communications equipment that provides information to passing vehicles.