Road Traffic Monitoring by Satellite (RTMS) is an innovative trial system that uses a fleet of tracer vehicles to detect congestion.
Using GPS position, an in-car computer and the ESA developed PRODAT mobile communication system, traffic data is reported via satellite to a central facility. Compared to conventional detection methods, a satellite-based in-car system offers better coverage and better data at potentially competitive costs.
Figure 1: Fleet of vans used
in the trial (click for larger
Congestion of public road networks is an increasing problem in many countries. As any traffic management strategy is only as good as the information it relies on, authorities need traffic data that is accurate, reliable, timely and comprehensive. Road users also need good quality traffic information in order to plan and adjust their routes.
The RTMS field trial, undertaken by ARS Traffic and Transport Technology (NL) and TU Dresden (D) with support from ESA Telecom s User Segment Programme line, started in March 1999 and was successfully completed in November 2002.
The trial took place in the busy Rotterdam and Den Haag districts of the Netherlands, and consisted of a pilot system installed in a fleet of 15 postal service and delivery vehicles. No interaction was necessary between the driver and the system during the trial.
Figure 2: The area covered
by the trial (click for larger
The large amount of usable data gathered from the vehicles demonstrated that the coverage of the satellite system is viable for collecting valuable real-time traffic data, even in densely urbanised areas.
Floating car data, the concept behind RTMS, works by using a relatively small percentage of the vehicle population to produce real-time traffic information, just by driving around. This allows for the collection of traffic data over the whole road network - not just bottlenecks - including towns, cities, rural roads and motorways not covered by GSM, GPRS or UMTS systems.
Figure 3: RTMS system
architecture (click for larger
The floating car data principle also gives information of better quality: tracer vehicles are able to produce travel times over a series of road segments, while traditional systems measure the traffic only at one point.
A satellite-based in-car system can provide many services in addition to traffic monitoring, such as fleet management, logistics support, emergency and breakdown service and theft protection. If integrated with other systems, it can provide real time route guidance and navigation information and location dependent services (such as locating the nearest bank at a given point during a journey).
For more detailed information on the system, please visit Related Links .