Caltrans D6 Connected Vehicle Infrastructure - Roadway Functionality

Subsystem Description

The Roadway Subsystem (RS) includes the equipment distributed on and along the roadway that monitors and controls traffic and monitors and manages the roadway itself. Equipment includes traffic detectors, environmental sensors, traffic signals, highway advisory radios, dynamic message signs, CCTV cameras and video image processing systems, grade crossing warning systems, and freeway ramp metering systems. HOV lane management, reversible lane management functions, and barrier systems that control access to transportation infrastructure such as roadways, bridges and tunnels are also supported. This subsystem also provides the capability for environmental monitoring including sensors that measure road conditions, surface weather, and vehicle emissions. In adverse conditions, automated systems can be used to apply anti-icing materials, disperse fog, etc. Work zone systems including work zone surveillance, traffic control, driver warning, and work crew safety systems are also included. To enhance security, safeguard systems such as blast shields, exhaust systems and other automated and remotely controlled systems to protect transportation infrastructure is also provided. In advanced implementations, this subsystem supports automated vehicle safety systems by safely controlling access to and egress from an Automated Highway System through monitoring of, and communications with, AHS vehicles. Intersection collision avoidance functions are provided by determining the probability of a collision in the intersection and sending appropriate warnings and/or control actions to the approaching vehicles.

Functional Area: Roadway Equipment Coordination

Field elements that control and send data to other field elements (such as environmental sensors that send data to a DMS or coordination between traffic controllers on adjacent intersections), without center control.

Functional Area: Roadway Intersection Safety Warning

Field elements that determine the probability of a collision in an intersection or at a railroad crossing and inform approaching vehicles using short-range wireless communications to the vehicles and traffic signal controls.

1The field element shall utilize traffic sensors to monitor vehicles approaching and occupying an intersection.Planned
2The field element shall monitor the operational state, signal timing, and current phase of the traffic signal.Planned
3The field element shall monitor road conditions on approaches to, and within, the intersection.Planned
4The field element shall communicate with approaching vehicles to determine vehicle position, velocity, acceleration, direction, and intended turning movement.Planned
5The field element shall detect potentially hazardous conditions including impending red-light or stop sign violations and potential conflicts between approaching vehicles.Planned
6The field element shall provide intersection status and warnings to approaching vehicles using field-vehicle communications.Planned
7The field element shall update signs or signals to warn the driver of potentially hazardous situations.Planned