"Traffic Speed and Counts with a Non-Invasive System provide ReliableTraffic Management and Traveler Information."
The TDS Traffic Measurement System involves the use of a unique traffic radar capable of tracking multiple vehicles in a roadway and determining the speed, position, and lane index for each one simultaneously. The radar is capable of performing the vehicle tracking even in complex situations. The figure below illustrates the radars derived knowledge representation of the traffic transitioning through the radar beam. An additional outcome of the radar processing is an accurate vehicle count.
The TDS concept includes a roadside processor interfaced to the radar which is used to manage the information produced by the ongoing radar data streams and to disseminate the data to a centralized processor. The radar and processor will be mounted on a roadside pole and together make up a sensor site. The centralized processor aggregates data from the sensor sites that are placed at key roadway locations. With the real-time traffic data available, speed and vehicle counts, a traffic flow model hosted on the centralized processor can determine estimates of the vehicle counts over time along the highway system and may be displayed on a GIS map or a related traffic management dashboard.
The use of a single pole mounted active sensor to detect vehicles and derive their associated velocities offers a number of significant advantages over competing technologies such as magnetic detection, license plate readers or radio transmission detection.
System advantages include:
- Highly accurate traffic counts and speed determination.
- Completely passive operations.
- All weather operation, high availability.
- No privacy concerns.
- Low installation cost without interference to traffic and without in ground components.
- No requirement for in vehicle radio transmission.
- Low maintenance cost – no moving parts.
- Long lifetime – No concerns with the effects of winter weather on in ground components.
- Self calibration / self diagnostics on board (i.e. sensor blind etc.)
This data when processed and transmitted to the traffic management system can provide continuous monitoring of the real-time traffic loads at critical roadway positions. The system can be configured to generate a warning when traffic volumes exceed certain preset thresholds. Site data can be easily redirected to a central fusion location for generation of overall flow across the entire length highway system being monitored.