All over the globe road operators face the challenges of growing traffic, congestion and the need to improve safety for the road users. For the most densely settled areas, large conurbations and heavily charged motorways, these challenges are crucial for the economic outlook. Therefore, road operators look into new ways that can help to keep traffic flowing and reduce safety impacts. They developed and use a variety of systems and approaches to outpace traffic growth and often with very good results.
New ways to cheaply and quickly add capacity and safety to existing road networks are needed. In Europe many road operators already rely heavily on systems like line control, variable message signs, electronic enforcement or traffic information services for running their network
Traffic Management in the past used to be clearly separated between police forces and road authorities. Roads had been recognised as a passive infrastructure, provided to the public and controlled by fixed rules and regulations. This is still true for some rural areas where sufficient capacity is available and recurrent congestion is no matter of interest. However for most regions, active traffic management can deliver significant and much needed gains in network performance.
Obviously traffic varies within and between days, weeks or seasons. Peak traffic that recurrently occurs asks for different rules applied than less critical situations. Dynamic speed limits, prohibiting overtaking, swift automatic incident detection and traffic forecast can avoid traffic breakdowns and keep traffic flowing.
As with other public commodities, the vast amounts of public investment and taxpayer’s money that flow into the road networks ask for good balance between expanding, upkeep and managing. To make the most of one’s roads intelligent transport systems are indispensable in the 21st century. These systems work like a chain of comprehensive monitoring, fast processing and exchanging information and finally choosing the measures best suited for a certain situation out of wide array of established instruments.
Monitoring the network
Monitoring represents the first and crucial link in the ITS [Intelligent Transport System] chain. These activities consume almost 25% of overall ITS expenditure in a heavily used road network. In the last years the monitoring quality in terms of density and availability has improved largely thus opening the door for new technologies like travel time estimation and forecast. Still inductive loops are the most common type of sensors, with radar, infrared, cameras or hybrid system following. Compared to motorways and interurban corridors hardly any monitoring can be found on the secondary road networks. But the need for traffic managing and fast incident detection concerns the whole road system. Floating probe data, coming from vehicles or phones as they move around has been recognised as a cure to this unsatisfying situation of today. Studies show that equipment rates of 5-10% should be sufficient to cover all but the most remote roads with basic traffic monitoring. However up to now no viable business case has been found to cover telecommunication and hardware costs and therefore such data remains scarce.
Road’s brain: Traffic control centres
Further on in the processing chain traffic control centres can be seen as the brain of traffic management from the road operator’s point of view. Traffic centres have expanded their area and means of operation and taken up new tasks in traffic management. Camera based supervision of critical road segments, switching variable message sings, activating and executing cross-border management plans and running construction site information and planning systems are amongst the responsibilities of state-of-the art TCC and TIC (Traffic Information Centres).
In recent years many Traffic Control and Information Centres have been either established or upgraded. New and cheaper communication technology, enhanced computer power and progress in traffic science have enabled proactive control and complete coverage. Despite the wide variety of organisational approaches, Traffic Centres are remarkably similar worldwide in terms of applications and technical requirements. Most of them are equipped 24/7, use large screens or video-walls for supervising, run traffic models to forecast or evaluate, keep close contact or are even manned by police forces and can react quickly on incidents or congestion.
Traffic Centres are the gateway to accurate and dynamic traffic message, travel times and traffic situation info for third parties like service providers. However while some road operators prefer to stay in the background when it comes to end-user-services others, many of them privately owned companies have made that field a focus area of their activities.
Restricted or piecemeal availability of data has been identified as a major obstacle to the much-wished growth of traffic information services, especially on large and international scale. This has also been recognised by the European Commission leading to the issuing of the recommendation 551 of 2001 on the development of a legal and business framework.
Focus on traffic management vital
Traffic management is the focus for road operators. It is often performed by use of variable message signs or by staff on the site. It includes quickly detecting incidents and traffic situation. It includes dynamic speed limits and enforcement to deter drivers from speeding and disregarding regulation. It includes giving advice for the best route to choose. And finally it includes numerous small-scale measures and installations to optimise road usage and to wipe out safety black spots.
Traffic Management must not stop at border between road operators, neither national nor merely organisational. Often drivers are not aware of alternatives in route choice when travelling foreign areas and suddenly traffic information is no longer available but in unknown languages and through unknown sources and distributors. Traffic management plans, involving two, three or more road operators offer a practical solution in case of recurrent network disturbance. The aim is to actually arrive at a seamless network operation where borders are no longer felt by the road user. Recurrent congestion and bottlenecks ask for the installation of fixed VMS-based systems whereas in other cases broadcast announcements and media base information might do. Centrico, a partnership of road operators and road authorities in Western Europe, identified the most relevant traffic corridors in early stages of their cooperation and now organise their activities around those crucial links.
Integrating traffic management and traffic information
The importance of access to dynamic traffic info is evident in the Information Society. Even if not all road operators regard operating traveller information services a core business of theirs, it is accepted that such services are of ever growing impact on traffic conditions. The Internet has multiplied the options for offering information to the general public without tremendous cost. Thus, Europe has seen a good number of sites and services develop, which are, however, not always as harmo-nised and understandable as would be required from the international road user.
Progress in technology now empowers road operators to rather accurately estimate travel times, congestion length and duration as well as the actual effects of bottlenecks like construction sites. Partly such information can’t be transported by conventional radio broadcast and asks for using other media, like VMS, Telephone Services, Websites, dedicated radio, GSM broadcast, mobile services or other.
Advancements during recent years have been considerable in this area. In 2001 hardly any level-of-service information could have been obtained from the Internet, but now the majority of road authorities run websites with a common look and feel, which, however, are not yet fully integrated.
Road Operators pursue different strategies on dissemination of information. Some prefer to act as a service provider in close parallel to traffic management; some rely on third parties to actually distribute information to the drivers. Yet, basic traffic information, and this includes traffic messages, level of service, travel times and construction site information and on “cheap” media like websites can be obtained for free almost everywhere. On top of that a growing number of commercial services have been established and offer personalised advice. However barriers still exist in getting and understanding the information for occasional and foreign drivers. Often they don’t know about the information on offer or don’t understand the language in which it is presented.
These obstacles could be overcome by a common Telephone number on traffic information similar to the 511 in the US. Centrico partners agreed to perform a scan on the potential benefits and the viewpoint of road operators to a European Traveller and Traffic Information Number, dubbed ETTIN. Such a service, if it is to be built up European-wide would rely on the set of 116xy numbers that are currently being reserved by the European Commission. Obviously Rod operators could only play a limited role in such a scheme but their engagement seems necessary to put the idea on tracks.
However, today there are more than 100 operators of the Trans-European road network and they manage their network according to dozens of different national frameworks. In the past road network construction and operation has been basically a nationally – or regionally – focussed area whereas other sectors in ITS like the intelligent car developed in the highly international environment of the automotive industry.
No wonder that in terms of network-wide harmonization and coordination of roadside equipment Europe is lagging behind the US and Japan. Thus, ITS often can’t be used in the most effective manner, foreign drivers, who are more and more numerous in multi-lingual Europe, can’t be assisted properly and ITS industry is still confronted with segregated markets where investments in developing systems is hard to justify. This situation is most severely felt where cross-border traffic is heavy, where there is long distance traffic overlaying with local traffic and where both goods vehicles and private cars have to be served.
Outlook: How smart future roads will be
The nineties saw acceleration in the usage of advanced technology to manage roads –decreasing costs for communication, monitoring, display technology and computer power coincided with advancements in knowledge and maturity of applications. Furthermore, drivers’ expectations have developed. The road operators are no longer regarded as remote engineers dealing with tarmac but are now expected to actively run the motorways to serve the public the best possible, disregarding actual borders in the spatial range of
Roads are expected to bear most of the growing traffic load in the coming decades. Even if the traffic growth tends to slow down in overall figures, the increases on crucial links and for freight traffic are unrelenting. Spatial developments, like the extension of the European Union, changes in industrial production and logistics and the shrinking effect of borders on mobility are causes that will keep their impact in the mid and long run. At the same time financial constraints lead into looking for cheaper and yet efficient ways to defend the performance of the road network. Intelligent Traffic management and information services can be a remedy in this situation. New technologies will be proactively treated by the road operators – Galileo and In-car systems are assessed to be most prominent. Huge benefits sleep in the closer cooperation between motorways and urban road or public transport networks. Even if these are not strictly part of the Trans-European Road Network obviously they define the performance of the transport network.
Urban roads and motorway network traffic management today are almost nowhere connected, in terms of traffic management, as traffic’s requirements are. Road User Charging is favoured by many cash stripped public road authorities to provide extra revenue. For heavy goods traffic many countries can be expected to introduce toll schemes in the years to come, some extending also to passenger cars. Obviously toll systems are closely connected to intelligent traffic management. Those systems can provide extra accurate data but also be used as incentives to pass by critical segments of the network if needed.
The accelerating developments of safety related technology in cars would lead to changed requirements for road operators. Some of today’s ITS applications might be rendered fall back solutions for the fleet of older cars. On the other hand already now we can make out new requirements like the support of databases on a variety of road-related information.
Again the international dimension has to be taken into account. Without active cooperation of road operators, which are closest to the road user, “island solutions” in ITS and a large assortment of VMS’s, data exchange systems, information services and procedural approaches will arise and some times be duplicated with but slight differences hampering the development of a truly Efficient Traffic Management for the world’s motorways.