DDOT Ramp Meters - Roadway Subsystem Functionality
Subsystem Description
This subsystem 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 Field Device Monitoring
Monitors field equipment operational status and detects and reports fault conditions. Device status, configuration, and fault information are provided to a remote center and a user interface provides information locally to field personnel.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall monitor the operational status (state of the device, configuration, and fault data) of connected sensors (such as traffic, infrastructure, environmental, security, speed) and devices (such as highway advisory radio, dynamic message signs, automated roadway treatment systems, barrier and safeguard systems, cameras, traffic signals, ramp meters, short range communications equipment, security surveillance equipment). | Planned |
| 2 | The field element shall send operational status of connected field equipment to the maintenance center. | Planned |
| 3 | The field element shall send collected fault data to the maintenance center for repair. | Planned |
Functional Area: Roadway Freeway Control
Freeway control equipment including ramp meters, mainline metering, and lane control equipment which controls traffic on freeways, including indicators to drivers.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall include ramp metering controllers, mainline meters, and lane controls for use on freeways, under center control. | Planned |
| 2 | The field element shall monitor operation of ramp meter, mainline meters, and lane control indicators and report to the center any instances in which the indicator response does not match that expected from the indicator control information. | Planned |
| 3 | The field element shall monitor operation of ramp meter, mainline meters, and lane control indicators and report to the center any instances in which the indicator response does not match that expected from known indicator preemptions. | Planned |
| 4 | The field element shall return ramp metering controller, mainline meters, and lane control operational status to the controlling center. | Planned |
| 5 | The field element shall return ramp metering controller, mainline meters, and lane control fault data to the maintenance center for repair. | Planned |