Jersey barrier

A Jersey barrier or Jersey wall is a modular concrete or plastic barrier employed to separate lanes of traffic. It is designed to minimize vehicle damage in cases of incidental contact while still preventing the crossover case of a head-on collision. Jersey barriers are also used to reroute traffic and protect pedestrians and workers during highway construction, as well as temporary and semi-permanent protections against landborne attack such as suicide vehicle bombs. A Jersey barrier is also known in the western United States as K-rail, a term borrowed from the California Department of Transportation specification for temporary concrete traffic barriers, or colloquially as a Jersey bump. Plastic water-filled barriers of the same general shape are also now commonly called Jersey barriers.

The Jersey barrier, also called New Jersey wall, was developed in the 1950s (introduced in current form in 1959), at the Stevens Institute of Technology,New Jersey, United States, under the direction of the New Jersey State Highway Department to divide multiple lanes on a highway. A typical Jersey barrier stands 32 inches (81 cm) tall and is made of steel-reinforced poured concrete or plastic. Many are constructed with the embedded steel reinforcement protruding from each end, allowing them to be incorporated into permanent emplacements when linked to one another by sections of fresh concrete poured on-site.

Their widespread use in road construction has led to wide application as a generic, portable barrier during construction projects and temporary rerouting of traffic into stopgap carpool and rush-hour reversing highway lanes.

The design of the Jersey barrier was specifically intended to minimize damage in incidental accidents and reduce the likelihood of a car crossing into oncoming lanes in the event of a collision. In common shallow-angle hits, sheet-metal damage is minimized by allowing the vehicle tires to ride up on the lower sloped face. Head-on collisions are minimized by gradually lifting the vehicle and pivoting it away from oncoming vehicles and back into traffic heading in its original direction.

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