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How The NEW JERSEY works> History of safety barriers
History of safety barriers

The median barrier of New Jersey is the tapered concrete barrier that is used in many main roads, to prevent lane jumps and redirect the vehicle in case of skidding. Even if it is not clear exactly when or where the first concrete median barriers had been used, surely the first elements to be installed were used in the mid-1940s on the US-99 on the descent from the mountains of Tehachapi in the south central part of Bakersfield valley, California.



The first generation of concrete barriers were developed to:

  1. minimize the number of trucks that lose control and invaded the opposite lane;
  2. eliminate the need for ordinary and extraordinary maintenance, very costly and very dangerous, in areas where accidents have occurred. Concerns that today stand as they did 50 years ago.

The first concrete median barrier was installed in 1955 in New Jersey, and was only 18 inches high. It resembled a low vertical wall with an edge on each side. The generated operational problems were observed and subsequently the shape was changed and the height was increased to 24 inches, and 32 inches in 1959 (the current height).
The state of New Jersey did not use crash-tests to develop the barriers. The technical department of the viability of the state of New Jersey observed the accidents that had occurred near the barriers and then evolved the shape of the barrier. Both the State of New Jersey and California, in the early 60's, continued experimentation, and the barriers designed by New Jersey, were widely adopted by California.
California installed, from 1972 to 1988, about 820 miles of barriers. Since then the use of the barrier has been adopted on almost all American roads.
In reality there are 6 designs of concrete median barrier, different from the known barrier, but the barrier of New Jersey was the one most successful.
Normally barriers with different profiles are commonly used on road borders such as, bridges rails, retaining wall tops, road embankments and against rock cuts. The first New Jersey profile barrier in modern concrete (that is, movable under impacts) were mounted in 1983 by Autostrade SpA on their roads with immediate positive results. Immediately noted were the DECREASES of jumps in the roadway medians, with obvious benefits.

Over the years, on Italian roads, thousands of kilometers of concrete safety barriers in New Jersey profile have been installed, and confirmed the general improvement of road safety, with a considerable saving in lives. Excellent results have occurred in the use of bridge borders, where the wall barriers prevent the fall of light and heavy vehicles and do not transmit the impact to the bridge. In 2005 was created a new profile for the median "T-Reverse" that would revolutionize the use of median strips avoiding small vehicles to rebound in the right lane, greatly improving their redirection.
In 2007, concrete wall barriers also entered into the world of concrete wall lateral borders; a number of barriers with new trapezoidal and redirective profiles, were placed on different media: concrete curbs, asphalt, oversite concrete, or keystone, etc.. etc..

In 2008, the first tests were performed on motorcyclists' impacts, obtaining quickly, excellent results. In fact motorcyclists, the road users who run the most risks, more than once, through their associations, have asked the road management bodies to install concrete wall barriers in the most dangerous areas, as they, with their continuity, do not give rise to rider impacts at sharp edges, often fatal.

In 2010 the controlled barrier displacement was born in order to protect any fixed point on roads, of which, bridge piers, retaining walls and lateral walls of galleries. Wall barriers require no maintenance after installation. Therefore do not generate maintenance costs and improve safety. In fact with the absence of maintenance, they do not give rise to maintenance sites, which could in turn generate possible accidents.




 
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