Cable barriers

A cable barrier, sometimes referred to as guard cable or wire rope safety barrier (WRSB), is a type of roadside or median safety traffic barrier/guard rail. It consists of steel wire ropes mounted on weak posts. As is the case with any roadside barrier, its primary purpose is to prevent a vehicle from leaving the traveled way and striking a fixed object or terrain feature that is less forgiving than itself. Also similar to most roadside barriers, cable barriers function by capturing and/or redirecting the errant vehicle.

Because these barriers are relatively inexpensive, as opposed to concrete step barriers to install and maintain, and are very effective at capturing vehicles, their use is becoming increasingly prevalent worldwide. By far, the most popular use of the cable barrier system occurs in the medians of divided highways.

Given the opposing directions of traffic on divided highways, cross median crashes are particularly severe. While median width plays a large role in the occurrence of these crashes, increased width alone does not eliminate them and quite often, the median must be shielded with a barrier. Cable barriers provide a cost-effective solution to the shielding issue.

The system is more forgiving than traditional concrete (Jersey) barriers or steel barriers used today and remains effective when installed on sloping terrain. The flexibility of the system absorbs impact energy and dissipates it laterally, which reduces the forces transmitted to the vehicle occupants.

Although cable barriers have been used since the 1960s it was not until the mid-1990s that many departments of transportation began to deploy them with any regularity.

In many countries of the European Union these cable barriers are not allowed to be used along highways as they perceived to be especially hazardous for motorcyclists. However, a study of motorcyclist injury rates for several types of highway barrier did not find an appreciable difference in fatal and severe injuries between cable barrier and W-beam barrier. Both were significantly more hazardous than concrete barrier, however were less hazardous than having no barrier at all.

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