In heavy goods vehicles and coaches speed limiters are used to impose international upper speed limits for these types of vehicles. These devices do however not adapt to local speed limits or prevailing conditions.
Intelligent Speed Adaptation (ISA) is a system by which the vehicle "knows" the permitted or recommended maximum speed for each particular road. This information can be used to inform the driver of the speed limit, warn him when he is exceeding the speed limit, or discourage or even prevent him from speeding.
Field trials have been carried out across Europe to test the different types of ISA, spreading from the SUN countries (Sweden, UK, Netherlands) to Denmark, Finland, Belgium, France, Austria and Norway. In 2003, trials were also conducted in two Southern and Eastern European countries (Spain and Hungary) which are currently being evaluated.
The ISA technology is based on three elements
A GPS-based navigation system "tells" the car where it is.
A digital road map on board the vehicle identifies the speed limit for this particular stretch of road.
This information is passed on to the driver either by a display on the dashboard or a so-called "active accelerator pedal".
The first two elements are becoming increasingly commonplace. More and more new cars have in-vehicle navigation systems as part of their original fitting. National digital road maps, incorporating speed limits, are almost complete for Sweden and Finland. In the Netherlands, a speed limit database has been made available on the internet which should become 98% accurate in two years time. The UK Department for Transport has also announced the creation of a speed limit database.
What still puzzles most experts is the question of how to update maps regularly so the vehicle always provides the same speed information as the traffic signs out on the road. So far, only Finland seems to have worked out a solution to this problem. The Finnish parliament passed at the end of 2003 legislation requiring municipalities to provide data so the digital map can be updated regularly.
The European Union is financing extensive research to accelerate both the development and deployment of ISA. The one-year SpeedAlert project, running until May 2005, is working out functional requirements and technical building blocks of an informative ISA. In the PROSPER project, obstacles to the implementation of ISA are being identified and arguments delivered to convince stakeholders and politicians of its use. Final results from PROSPER are expected in December 2005.
Other research projects are expected to deliver solutions to the problem of high-quality, updated digital maps and infrastructure-vehicle communication.
The EuroRoads project, launched in March 2004, aims to lay the ground for the creation of a EU-wide harmonised and quality assured digital road data infrastructure.
The ActMAP project will present before the end of 2004, mechanisms for dynamic updates of digital maps used for in-vehicle ITS applications.
MAPS&ADAS aims to develop until 2007 a standardised interface to access map and positioning data from various ITS applications, including ISA, and the Safety Channel project will develop and validate the "safety channel" concept for real-time communication of traffic information, including variable speed limits.
Sweden has in the meantime started to move from research to actual deployment of the ISA technology. The Swedish Road Administration (SRA) is planning to buy 150 ISA devices for its own fleet, and from 2005 subcontractors will need to have ISA installed in their fleet as well. In Norway, 200 cars of novice drivers will be equipped with the technology, and Denmark plans to offer reductions on insurance premiums for young drivers if they fit ISA into their cars.
Car manufacturers are divided on the issue. While some producers (e.g. Volkswagen) are ready to offer ISA to their customers, others remain sceptical claiming they would be made liable for accidents in case the system was not functioning properly. The Association of European Carmakers (ACEA) therefore calls for a "supportive" system that would be used on a "voluntary" basis so that the driver remains fully in control at all times.
National ISA trials:
Netherlands (final report)
Finland (final report)
Political support for Intelligent Speed Adaptation (ISA) in the Netherlands (SWOV, 2004)
Technologies for speed control. Possibilities and support for intelligent speed adaptation