Pros and cons of various types of barriers
A frontal collision is very serious compared to other types of crashes on the highway. It takes only seconds for vehicles traveling at highway speeds to cross the median and collide with vehicles on the other side of the lane. Median barriers are effective in physically separating opposing traffic streams from a highway. It also helps stop vehicles that accidentally cross into the oncoming lane and prevent pedestrians from crossing the road at risky locations. In 2006, there were 821 median crossing crashes resulting in fatalities on the US national highway system alone.
Factors that influence the selection of a barrier system are the type of vehicles involved, the geometry of the roadway, and the potential severity of any frontal crash incident. In most places, a standard barrier capable of redirecting vehicles to the correct area would suffice. However, in places with complex geometry, adverse environmental conditions, heavy truck traffic, and high traffic volumes and speeds, a high-performance barrier is necessary.
There are basically three categories of medium barriers. Are detailed below,
rigid barriers
The most common type of median barrier in use today are concrete barriers.
Advantages:
– They are widely used due to their maintenance free features, low life cycle cost and safety performance.
– They are very effective in avoiding cross-vehicle collisions in accident-prone regions with high traffic volumes and speed.
– They can also be used in areas where the median widths necessary to install other types of barriers are not available.
– The Jersey barrier is a modular concrete barrier that allows vehicles to collide on its inclined lower face, pivoting it back in its original direction.
Cons:
– Comparatively the installation cost of rigid barriers is high.
semi-rigid barriers
It is also called a railing or railing. These rails are made of metals and are collected in segments supported by posts or blocks.
Advantages:
– Unlike rigid barriers, semi-rigid barriers are designed to absorb more impact energy and the entire assembly moves or deflects during the crash. Therefore less damage to the vehicle.
– The installation cost is lower.
Cons:
– They are only suitable for areas that are not neglected and have good soil conditions.
– The cost of repair after an impact is high.
cable barriers
It usually consists of several wires that are connected together on a series of posts.
Advantages:
– It is the most versatile and forgiving barrier system to minimize median crossover crashes. It absorbs most of the impact energy and reduces the forces exerted on vehicles and their occupants.
Cons:
– A lot of time and money must be spent on maintenance, endangering motorists and workers during each repair.
The other factors that are considered before deciding on the type of barrier are road alignment, crash history, and the number of lanes.