Caltrans D6 Environmental Sensor Stations - 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 Basic Surveillance
Field elements that monitor traffic conditions using loop detectors and CCTV cameras.
Functional Area: Roadway Environmental Monitoring
Environmental sensors, surface and sub-surface, that collect weather and road surface information. Weather conditions measured include temperature, wind, humidity, precipitation, and visibility. Sensors measure road surface temperature, moisture, icing, salinity, etc.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall include surface and sub-surface environmental sensors that measure road surface temperature, moisture, icing, salinity, and other measures. | Planned |
| 2 | The field element shall include environmental sensors that measure weather conditions including temperature, wind, humidity, precipitation, and visibility. | Planned |
| 3 | The field element's environmental sensors shall be remotely controlled by a maintenance center. | Planned |
| 4 | The field element's environmental sensors shall be remotely controlled by a traffic management center. | Planned |
| 6 | The field element's environmental sensors shall be remotely controlled by a maintenance and construction vehicle. | Planned |
| 7 | The field element shall provide environmental sensor equipment operational status to the controlling center or maintenance vehicle. | Planned |
| 8 | The field element shall provide environmental sensor equipment fault indication to the controlling center or maintenance vehicle. | Planned |
| 9 | The field element shall remotely aggregate environmental sensor data with environmental data collected from maintenance and construction vehicles. | Planned |
| 10 | The field element shall provide weather and road surface condition data to centers. | Planned |
| 11 | The field element shall provide weather and road surface condition data to maintenance and construction vehicles. | Planned |
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 Probe Data Communications
Field elements that collect probe data from vehicles using short range communications.
| ID | Requirement | Status |
|---|---|---|
| 7 | The field element shall provide roadside equipment operational status to the center. | Planned |
Functional Area: Roadway Short Range Traveler Information Communications
Field elements that distribute information to in-vehicle equipment. The information provided may be determined locally or under the control of a center.