Articles in Taxonomy

Speed control by improving road legibility – Self-explaining road concepts

It is generally accepted that human error is involved in a good many road accidents. Although education, awareness and enforcement are important tools in reducing the number of accidents, it is equally crucial that the road environment and the vehicle should be adapted to the limitations of human abilities.


Space – Speed Adaption Control by Self-Explaining Roads

The objective of the SPACE project was to identify solutions that offer the greatest potential safety gains. A literature review was made for that purpose, and a panel of experts evaluated a number of promising treatments by means of interactive visual tools and through experiments in a driving simulator.

Skid resistance / Slipperiness

Areas of Expertise (1)


Skid resistance is defined as the frictional resistance at the interface between a vehicle tyre and the road surface. It plays an important part in the safety of road users: a correlation has been demonstrated between the skid resistance of pavements and accident rates (see the diagram opposite) [of course, there are many other possible causes of accidents: human error, vehicle technical failure, weather conditions, other infrastructure-related factors, etc.]. Wet pavement skid resistance is considered here, since dry pavement skid resistance is rarely a problem. A rough contact between the road and the tyres makes it possible to utilize the friction forces in braking. These friction forces also allow easier cornering. As a result, it is obvious that road managers should pay much attention to skid resisistance and alert road users in time of any local problem with poor skid resistance, and also that they should replace the pavement as soon as possible by an adequately skid-resistant pavement.

Passively safe support structures for road equipment

A little less than 40 % of all road fatalities result from collisions with roadside obstacles. Collisions with such isolated obstacles are about twice as lethal as on average and cause 1.6 times more serious injuries as on average. Natural obstacles (such as trees) are by far the largest group. Additionally, considerable numbers of lives are lost in collisions with lighting columns and other road equipment.
Collisions with lighting columns and other robust support structures account for slightly less than 10 % of the total number of road deaths. Yet for lighting columns and for sign or signal poles there are alternatives that are not inferior in functionality to conventional rigid structures. This makes a major difference for the occupants of a passenger car running into such a support structure.


Geometric inspection of raised traffic calming devices on public highways: road humps

Raised traffic calming devices (road humps) which are meant to reduce the speed of traffic on public highways to a maximum of 30 km/h have to meet the siting conditions and technical specifications laid down in the royal decree of 3rd May 2002, which has amended a previous royal decree of 9th October 1998. The changes introduced by the new decree consist mainly of tolerances in dimensions.