Top Reasons to Install W-Beam Steel Guardrails on South African Roads

The W-beam guardrail has become such a familiar sight next to highways and on mountain passes in South Africa, that few people even consider the importance of having these barriers in place. In this article, we take a closer look at the reasons for installing barriers.

Other names for guardrails

w beam guardrail

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Guardrails are known by names including highway barriers, steel barriers, removable railing systems and traffic barriers. When installed in urban areas between the walk areas and the highways or busy urban roads, the guardrails are often called pedestrian rails. In these instances, the guardrail serves a two-fold purpose:

  • Prevents pedestrians from simply walking across the road, thereby endangering their lives and that of other road users;
  • Prevents vehicles from straying into pedestrian or cycle areas by accident or on purpose, posing a danger to the users of the demarcated area.

Prevents crossing over from one highway to another

When placed in the median grass area between two opposite flowing highways, the guardrails are called median barriers. Unlike the ones found at the edge of the road with only beams attached on one side of the wooden or steel posts, these feature steel beams on both sides of the wooden posts. This is to protect against impact from both sides.

Prevents vehicles from colliding with hazardous objects

When a motorist loses control of their vehicle and the vehicle strays from the safety of the road, the risk of a collision with an unforgiving object is high. If the vehicle collides with an object like a tree, wall, culvert inlet or pole then the full impact of the collision is taken by the vehicle and its occupants. Depending on the speed of travel, the impact can be enough to damage the vehicle to such a degree that the occupants suffer serious injury or die as a result of their injuries. To reduce the risk, it is necessary to install a guardrail between the road edge and any hazardous objects.

In this instance, the barrier serves to prevent collisions with hazardous objects. Although the impact with the barrier can also cause extreme damage to the vehicle, in most instances the damage is less than would have been the case, had the vehicle collided with the hazardous object. The barrier takes the collision’s impact energy, absorbs and distributes it across the entire system, thereby reducing the force of impact on the vehicle and its occupants. It has the potential of saving lives.

Prevents a vehicle from vaulting over

High ground clearance vehicles travelling at high speed on a national road, or a highway are at risk of vaulting on impact with the barrier. To prevent such, higher posts are installed. The posts give way just enough to absorb some of the kinetic impact energy from the collision, whilst ensuring enough deflection to prevent the vehicle from vaulting over. The impact energy is distributed across the system, thereby reducing the impact on the vehicle and its occupants. The vaulting prevention is made possible with higher posts and mounting, and larger block-outs.

Prevents straying vehicles from going down steep slopes or over cliffs

Mountain passes are especially dangerous travel paths. Winds, sharp curves, rock falls and little room for error add to the danger. Just a slight stray from the road can cause the vehicle from going over the side of a cliff. To make mountain passes safer, guardrails are installed. Should a vehicle stray and hit the barrier at a slight angle, the friction caused by the metal of the vehicle and the steel from the barrier helps to reduce the speed of the vehicle. At the same time, the vehicle is redirected back to its original path. Given the importance of the barrier in this type of situation, it’s essential to ensure correct installation with the right distance between the posts and the correct height of the barrier.

Shows where the edge of the road is at night

This is extremely important on mountain passes where it is already difficult to judge exactly where the road ends and where the cliff starts. With the barrier fitted with delineators that light up when a vehicle’s light shines on them, the barrier is highly visible. This shows the motorist where the edge is on turns, also helping a motorist when an oncoming vehicle’s lights make it difficult to judge exactly where the road turns.

Prevents median clustering at night

Median clustering is the practice of driving just left from the median line. This is extremely dangerous, especially when two vehicles travelling in opposite directions do the same, increasing the risk of the two colliding. Even the slightest impact can cause a serious accident since the vehicles might travel at high speed and vehicles travelling behind them can also be affected by the incident.

The installation of the barrier at the left edge of the road shows the motorists where the edge of the road is, giving them the confidence to keep to the left, thereby reducing the risk of a head-on collision.

Prevents vehicles from performing dangerous actions

When installed in the median of two opposite direction highways, the guardrail prevents vehicles from crossing over to the fast lane of the opposite direction highway.

Prevents accidents from spilling over opposite direction highways

An accident in the fast lane of, for instance, a highway running in a southern direction can easily spill over to the fast lane of a northern flowing highway. This could escalate an already potentially fatal situation, especially because the vehicles are travelling at high speed. With the highway guardrail higher than the one found in urban areas, it is possible to prevent this type of incident.

Prevents roll-over as the result of impact

The primary function of the guardrail is to prevent the vehicle from leaving the safety of the road and moving into oncoming traffic. That said, if there is no barrier on the side, a vehicle can easily roll over when its wheels hit the gravel. Also, the barrier helps to keep the vehicle in an upright position upon side impact.

These are just some of the many benefits of having quality guardrails installed on South African roads. Quality materials and correct installation contribute to the safety of these barriers for road users. Make sure you get the right products and expert installation guidelines. View the road safety barriers available from Armco Superlite in South Africa.