6,000 Vehicles Test ISA in Sweden
IV Quarterly Issue #3
October 1999

Intelligent Speed Adaptation (ISA), considered a radical approach by some, is gaining in momentum in Europe.  The Swedes are gearing up for the largest test to date of the controversial vehicle speed regulation system, with multiple sites and diverse technologies slated for evaluation.  In response to an IVQ request, Anneli Johansson of the Swedish National Road Administration graciously provided the following article on activities in his country.

The Swedish National Road Administration (SNRA) is about to run a large-scale trial involving Intelligent Speed Adaptation (ISA) in urban areas, based on experience acquired from previous smaller-scale trials (research in this area has been in progress in Lund since the start of the 1980s).

Approximately six thousand cars will be equipped with voluntary speed adaptation systems to help motorists keep to the speed limits.  The SNRA will be investing a total of 75 million Swedish Krona (approx. US$9 million) between 1999 and 2001.  This trial will be conducted in collaboration with four municipalities and will aim to increase our knowledge of:

• motorists’ use and attitudes

• the effects on traffic safety and the environment

• the integration of these systems in cars

• the prerequisites for the large-scale use of road informatics

Impetus: Increased Safety

In the autumn of 1997, the Swedish parliament approved the government proposal that all traffic safety work be based on the ”Vision Zero” -- a goal of zero fatalities or serious injuries on the roads, and somewhat of a reversal in the trend of traffic safety programmes.  Although studies reveal that virtually everyone feels that it is important to keep to the speed limit, more than half the people interviewed stated that they had frequently or fairly frequently driven too fast during the past year.  The ISA trial aims in part to help understand the link between the danger to which we are exposing ourselves and our environment.

Four Trial Areas

Borlänge, Lidköping, Lund and Umeå are the trial cities, and are responsible for running the trial in the individual areas.  The SNRA is coordinating the project at the national level and provides project management, technical support and evaluation coordination.  Different groups of road users are included in the trials: private individuals account for the largest group, but professional road users, working for both private businesses and public authorities (including public transport vehicles), also account for a significant percentage.  The number of test vehicles is distributed as follows:  Umeå — 5000, Borlänge — 400, Lidköping — 300 and Lund — 300.

Range of Systems to be Tested

Different systems and different technical solutions are being tested in the four trial areas -- all first-generation prototypes.  Only vehicles from the 1989 model year and later will participate in the trials, due to the need to tap the cruise control system’s speed sensor.  The systems operate as follows:

Informative ISA System.  A box with a warning function is attached to the dashboard.  When the driver exceeds the speed limit, a lamp flashes and a sound signal is heard.  Both private motorists and professional drivers in Umeå, Borlänge and Lidköping are testing this system.  In Borlänge and Lidköping, there is also a display which shows the current speed limit in the test area.

Actively supporting ISA systems.  This system is also known as the ”active accelerator.”  When the driver attempts to exceed the maximum permissible speed, slight resistance in the accelerator is activated.  The driver is informed without needing to take his/her eyes off the road to look at the speedometer.  If necessary, the driver can disconnect the system by depressing the accelerator somewhat harder, otherwise known as a kick-down function.  Both private motorists and professional drivers in Lidköping and Lund are testing this system.

Quality assurance systems will be tested on municipal transport vehicles such as school taxis and transport for the disabled, with the aim of providing a basis for assuring the quality of traffic safety.  The test vehicles will be equipped with a unit which registers and stores any speed violations, measured as driver failure to reduce speed in spite of warnings over a period of 10–15 seconds.  The transport purchaser will then receive a “receipt” proving that the carrier has complied with the agreement to maintain speed limits.  This system is being tested in Borlänge.

Technology and Evaluation

Two different technologies are being tested to provide position information to the on-board ISA computers: GPS with digital maps, and roadside transmitters.  In Lund, Lidköping, and Borlänge, a differential GPS receiver will be fitted in the test vehicle.  The vehicle does not transmit a signal of its own and cannot therefore be localised.  The GPS is supplemented with a digital map of the test area, which includes the current speed limits.  In Umeå, transmitters along the sides of the road, next to speed signs, are being tested.  These transmitters send a signal to the test vehicles informing them that they are in the test area and specifying the speed limits that apply.

The project will be evaluated from four angles:  What does the user think?  How can the technology be integrated with the driver?  What are the effects on safety and the environment?  What is the general attitude to traffic safety?  Each municipality will conduct its own local evaluation, coordinated nationally.  In principle, the evaluations will be based on comparative measurements before, during, and after the introduction of ISA systems.  There are relatively large differences in the design of the trial in the four trial areas and this will be taken into account when planning the field measurements and comparing the evaluation results.

Next Steps

Using Intelligent Speed Adaptation (ISA), many current traditional systems can be supplemented with ‘smart’ systems, to not only help motorists reach destinations smoothly, safely, and conveniently, but to also make life more secure for other road users at the same time.  For instance, physical speed obstacles might be someday replaced with “electronic speedbumps,” with the permitted speed easily adapted to match the prevailing conditions.

Because only small-scale trials with ISA have been conducted in the past, SNRA looks forward to sharing the results of this first large-scale trial with the many traffic researchers all over the world who are following the study with great anticipation.

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For More Information ...

... contact Anneli Johansson of the Swedish National Road Administration at anneli.johansson@vv.se.

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