Clovis Vehicle Detection Systems - 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.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall collect, process, digitize, and send traffic sensor data (speed, volume, and occupancy) to the center for further analysis and storage, under center control. | Existing |
| 2 | The field element shall collect, process, and send traffic images to the center for further analysis and distribution. | Existing |
| 3 | The field element shall collect, digitize, and send multimodal crossing and high occupancy vehicle (HOV) lane sensor data to the center for further analysis and storage. | Planned |
Functional Area: Roadway Data Collection
Field elements to collect traffic, road, and environmental conditions information for use in transportation planning, research, and other off-line applications. Includes the sensors, supporting roadside infrastructure, and communications equipment.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall collect traffic, road, and environmental conditions information. | Existing |
| 2 | The field element shall include the sensors and supporting roadside devices that sense, collect, and send traffic, road, and environmental conditions information to a center for archival. | Existing |
| 3 | The field element shall collect sensor status and sensor faults from roadside equipment and send it along with the recorded data to a center for archival. | Existing |
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.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall include sensors that provide data and status information to other field element devices, without center control. | Existing |
| 2 | The field element shall include sensors that receive configuration data from other field element devices, without center control. | Existing |
| 3 | The field element shall include devices that provide data and status information to other field element devices without center control. | Existing |
| 4 | The field element shall include devices that receive configuration data from other field element devices, without center control. | Existing |
Functional Area: Roadway Probe Data Communications
Field elements that collect probe data from vehicles using short range communications.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall communicate with passing vehicles for traffic data link time calculations and send collected data to the controlling center; identification will be removed to ensure anonymity. | Planned |
| 2 | The field element shall communicate with on-board equipment on passing vehicles to collect current vehicle position, speed, and heading and a record of previous events (e.g., starts and stops, link travel times) that can be used to determine current traffic conditions. | Planned |
| 4 | The field element shall communicate with on-board equipment on passing vehicles to collect vehicle trip information (e.g., origin and destination information, travel times) that can be used to support transportation planning. | Planned |
| 5 | The field element shall communicate with on-board equipment on passing vehicles to collect a history of precise positioning information that can be used to derive or verify accurate roadway geometry and lane features for use by map update providers. | 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.