Vehicle restraint systems (VRS) are structural installations. Their task is to intercept, deflect or bring vehicles to a standstill and thus minimise serious consequences for people and the environment. Examples of such systems are crash barriers and impact absorbers. They prevent vehicles from reaching people, buildings or critical systems unhindered. They are therefore an essential but often forgotten part of any holistic safety strategy. The evolution of restraint systems from rigid beginnings to modern, energy-absorbing constructions made of high-strength steel or composite materials shows the continuous development in this safety-relevant area.
When protection starts at the edge of the carriageway
One driving error, slippery road surface or a little carelessness – and a vehicle can veer off the road.Anyone who has not planned an effective restraint system at this moment is exposing themselves and others to unnecessary risks.A single vehicle is enough to cause major damage, especially at properties near busy roads, at depots or at facilities with increased protection requirements (e.g. substations, data centres, waterworks or other critical infrastructure facilities).Restraint systems have a preventive effect here: they divert vehicles in a controlled manner, absorb kinetic energy and thus protect both human lives and operational assets.Well-designed systems also reduce the G-forces acting on the vehicle occupants, which minimises the risk of injury.
Common mistakes in practice
Despite their importance, restraint systems are often used incorrectly or completely forgotten.Typical planning errors:
- Confusion with barriers: Restraint systems provide lateral protection – other solutions, e.g. tested and certified safety bollards, help against a frontal impact).
- Lack of space for the effective area (W): The lateral distance between the edge of the carriageway and the maximum dynamic deflection of the restraint system in the event of a collision must be free of obstacles.Systems need this deformation space – anyone who ignores this risks an ineffective or even dangerous design.
- Wrong choice of system: The requirements differ depending on the traffic, terrain and protected object – a standard system is not always sufficient. The containment level (performance level) according to the European standard EN 1317 – which describes the ability of an FRS to contain vehicles of different sizes and speeds – must be carefully matched to the specific risks.
- Non-compliance with minimum lengths: Restraint systems must be installed at the tested system length, otherwise they lose their protective effect. Failure to observe the minimum length can significantly impair functionality.
Safety begins with planning
Those who include restraint systems in their safety considerations at an early stage not only save costs – a cost-benefit analysis often shows the long-term cost-effectiveness through avoided damage, but also noticeably increase the protective effect.In particular, those responsible for safety should
- Evaluate the type and frequency of traffic in the neighbourhood,
- consider potential collision scenarios (e.g. slipperiness, distraction, targeted passage) and also include the impact angle and impact speed in their considerations, which are simulated in test procedures.
- and plan with sufficient distance to the system to ensure deformation and protection. Pay attention to the required effective range.
Compliance with the European standard EN 1317 is essential, as it standardises the performance assessment (containment level), the impact area and the impact severity (ASI) – a measure of the severity of the impact on the vehicle occupants.Country-specific differences in the guidelines may also need to be taken into account.
Particular attention should also be paid to transition structures between different systems or to fixed structures, as well as end designs to minimise the risk of impalement.
A topic for every protection strategy
Vehicle restraint systems are not an add-on – they are an integral part of modern physical security.Particularly in sensitive areas or exposed properties, it is essential to incorporate this protective measure into the security architecture. The use of adequate restraint systems may even have a positive impact on insurance premiums.
You can find out more about technology, planning and common mistakes when using vehicle restraint systems in our latest podcast episode of ‘Fill the Gap – the Security Podcast’. From 29 May 2025 everywhere there are podcasts.
