When thinking of crash barriers as road safety products, the picture that might come to mind may vary from the conventional guardrail to prevent cars from driving off a cliff to sand-filled arrestors beds next to roads to reduce the momentum of and stop runaway trucks. There are many road-safety products that one could mention.
Barriers can be distinguished based on their placement. The ones installed in the middle or grass section between the opposing lanes of double-carriageway highways are known as median barriers. These barriers serve to prevent motorists from crossing the median into oncoming traffic and also helps to prevent an accident in the fast lane of one carriageway from spilling over into that of the oncoming one. It thus mainly serves to prevent crossover from one carriageway to the other. When it is installed on the side or shoulder of the road, it serves several purposes, also dependant on the flexibility of the barrier. The W-beam metal rail serves to indicate the side of the road, to redirect straying vehicles back into their original paths and to prevent them from hitting unforgiving objects behind the rails. As such, it improves the safety profile of a section of road.
Types of crash barriers can further be distinguished based on the flexibility of their rails. The wire-rope fence is made from wire rope that is suspended between support posts. These barriers take up little space and are thus the ideal safety products to use where there is insufficient space between lanes to allow for the installation of concrete blocks or the more conventional W-beam guardrail system. Wire-rope barriers redirect vehicles upon angled impacts. The system also prevents straying vehicles from hitting unforgiving objects. Called flexible because of the wire rope, these systems are often used where different types of traffic lanes are allocated. To prevent motorists from using lanes allocated to other types of traffic, wire-rope systems may be installed.
The wire-rope system is designed to absorb most of the impact energy and distribute it along the entire post section. As such, it acts to reduce the severity of a high-speed impact on a vehicle and its occupants and thereby reduce the damage to the vehicle and injuries to its occupants. It is also one of the products forming part of our range. Semi-rigid barriers are also widely used safety products and the W-beam galvanised steel barrier is an example. It is not as flexible as the wire-rope system but not as rigid as a concrete barrier. The W-beam is the most common and conventional guardrail discussed earlier. If it is installed in the median section of a double-carriageway road, it has steel panels to both sides of the support posts to protect against impact or breakthrough from both sides. This type of barrier absorbs a part of the impact energy and disperses it, while also acting as a barrier to prevent breakthrough. It has a wider surface footprint than the wire-rope system.
Rigid barriers are inflexible and such barriers serve not so much to reduce the severity of an impact as to prevent breakthrough altogether. These safety products are placed in the median of dual-carriageway highways where there is little space and no grass median. These concrete barriers can also be installed on the sides of highways. One can, furthermore, distinguish between crash or safety barriers based on whether they are intended for permanent or temporary use. Water-filled barriers are, for instance, placed where motorists must be separated from temporary hazards or workers separated from motorists. The water (or sand) in the barriers serve to prevent them from being moved or blown over by winds and they do not act as impact cushioning.
Another of the safety products typically used as a temporary barrier is the truck-mounted attenuator. It shows motorists that there are roadside works taking place in front of the truck and that vehicles must slow down or pass the vehicle in the appropriate next-available lane. The truck-mounted attenuator also serves to protect the workers and equipment in front of the truck against high-speed impacts from vehicles.
This is but a short introduction to barrier types. View our full range of road-safety products and call us for assistance in selecting the appropriate type of barrier for your application or needs.