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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.

The consequences of a collision with passively safe support structures can be evaluated by a method described in standard NBN EN 12767 Passive safety of support structures for road equipment – Requirements, classification and test methods. Using the results of (most often two) impact tests, a structure can be ranked into performance classes for:

  • energy absorption level;
  • impact speed;
  • vehicle occupant safety level.

Manufacturers of lighting columns and other support structures for road equipment have invested in the development of passively safe products since the year 2000. In 2010, passively safe lighting columns became the standard choice – with a few exceptions – of the Flemish public authorities for newly installed lighting along regional roads (official order MOW/AWV/2010/6). Since then, accidents with passively safe structures have demonstrated several times that the system really works.

Not all locations are suitable for the installation of a passively safe support. Relevant recommendations can be found in a circular of the Flemish agency for roads and traffic (AWV), or can be obtained from BRRC.