Traffic Management

Applications
Title	Traffic Management
Author(s)	Rui Barradas Pereira.
Level	Basic
Year of Publication	2011

Congestion of public road networks is a growing problem in many countries. Authorities are developing initiatives to manage the traffic, but no remedial strategy can be better than the information upon which it has to rely. Consequently, the traffic planners need information that is accurate, reliable, timely and complete. The road users too need good-quality traffic information in order to plan and adjust their routes.

The monitoring and management of traffic fluidity will be significantly facilitated when a great number of cars are equipped with satellite navigation receivers and guidance systems. For example, if the average speed of the cars equipped with GNSS receivers in a road sector drops significantly, a control center can anticipate a traffic jam and suggest that approaching vehicles choose different routes. Several studies have concluded that travel time would be cut by 10-20%.

Application Characterization

The use of GNSS for traffic management has been envisioned by authorities all over the world. With the growth in traffic more traffic information is required to regulate traffic flow and guarantee traffic safety. With additional traffic information the road infrastructure can be optimized by guiding traffic and controlling the traffic flows. Such systems would be able to provide route guidance, in case of traffic jams, incidents or road works.

Traffic information has traditionally been collected with inductive-loop detectors embedded in the roads and with video cameras. These fixed installations do not give any traffic information beyond the locations where they are installed, and their coverage is usually confined to congestion-sensitive motorways and a limited number of tunnels, bridges and intersections.

The gathering of ‘floating-car’ data is a totally different concept, whereby a relatively small percentage of the vehicle population generates real-time traffic information just by participating in the traffic flow. The data being collected by the participating vehicles is immediately communicated to a central facility for processing. This approach allows the collection of traffic data across the whole road network – including towns, cities, rural roads and currently unmonitored motorway segments. Floating-car data also has the potential to provide better-quality information. The tracer vehicles can log travel times over a series of road segments, whereas traditional systems measure the traffic only at specific points. In addition, tracer vehicles can detect and report various types of traffic ‘events’ as they occur.

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.

Other possibilities include warning drivers of traffic jams and suggesting alternative routes; providing drivers with accurate and up-to-the-minute information on motorway lane closures and speed restrictions; and guiding drivers to the nearest parking space, hotel, restaurant or other facility. The list is almost endless.

Currently, traffic management is being done using traffic information generated by inductive loops and cameras in the road. This approach requires intervention on the road for the installation of this equipment. Given the costs of the installation of such equipments that usually will cover only the main road network authorities have be

As such, the traffic manager is depending on reliable traffic information. At this moment, traffic information is generated by inductive loops in the road, only available on the main road network. In the near future, Rijkswaterstaat investigates other technologies to obtain traffic information. One of these technologies is Global Navigation Satellite Systems, in particular EGNOS and Galileo.

VCNL has defined their wishes for Traffic Management and Incident Management in relation to ARMAS and expressed the need for information about traffic flows (speed, intensity and location at any point in time). The main question that VCNL raises is: How can ARMAS assist in obtaining this data per road segment with a defined frequency and quality. The wishes and needs has been defined in the document “Gebruikerswensen ARMAS” which is attached in appendix A. Their needs are compiled into User Requirements in this document.

The gathering of ‘floating-car’ data is a totally different concept, whereby a relatively small percentage of the vehicle population generates real-time traffic information just by participating in the traffic flow. The data being collected by the participating vehicles is immediately communicated to a central facility for processing. This approach allows the collection of traffic data across the whole road network – including towns, cities, rural roads and currently unmonitored motorway segments. Floating-car data also has the potential to provide better-quality information. The tracer vehicles can log travel times over a series of road segments, whereas traditional systems measure the traffic only at specific points. In addition, tracer vehicles can detect and report various types of traffic ‘events’ as they occur.

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.

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).