Temporary Road Safety Barriers

VRS stands for Vehicle Restraint System. These systems, such as guardrails or parapets, are crucial in preventing errant vehicles from entering restricted areas or causing harm to pedestrians and infrastructure.  They are often used to improve road safety and protect vulnerable areas, such as roadside construction and maintenance.

Each barrier system tested to EN 1317 is awarded a working width class. This is calculated by adding the width of the system plus the amount of deflection that occurs when the system is impacted to the test criteria. The system’s deflection is measured from the traffic face of the system.

So, for example: For a system with a working width of W1, the total system dynamic deflection combined with the barrier width will not exceed 600mm, whereas a system with a performance level of W3 will not exceed 1000mm.

The system is measured from the traffic face of the VRS before impact, to the rear-most point of the VRS after impact i.e. how far the hazard needs to be away from the traffic face and not be impacted.

Please see relevant system manual for the minimum recommended values for length in approach of and depart of the hazard.

The length of our guardrail systems are based on a full-height length of need NOT including the need for terminals at either end. This ruling ensures the system would fall in line with the minimum length of full containment referenced within CD377, rounded up to suit the nominal length of beam. This guidance is applicable for motorway and all-purpose trunk roads with speed limits of 50 mph or more.

For scenarios where a shorter length may be required or there are other limitations, please contact a member of our Technical team at technical@hill-smith.co.uk and we will be able to advise accordingly.

Containment levels are determined through impact tests where a vehicle of a specified mass and speed is driven into a barrier. The barrier’s performance is assessed based on factors like:

• Vehicle penetration: Whether the vehicle breaks through the barrier.
• Vehicle trajectory: The path the vehicle takes after impact.
• Occupant risk: The level of risk to the vehicle occupants.

Impact tests are carried out in accordance with EN 1317-2 and determine key performance indicators such as containment level, working with, vehicle intrusion and impact severity levels.