A Jersey barrier is a modular concrete or plastic barrier with a sloped profile used to separate traffic, protect roadway work zones and channel vehicles or pedestrians away from hazards.
A Jersey barrier is a modular, portable barrier with a distinctive sloped profile, wide at the base and narrower at the top, used to separate traffic lanes, protect work zones and channel vehicles or pedestrians. The name comes from the shape's origins in New Jersey highway design. Today the term is used broadly for precast concrete safety-shape barriers and, informally, for lighter plastic barriers that copy the same shape.
The sloped face is designed so that a vehicle striking the barrier at a shallow angle rides up the lower slope, which helps redirect it back toward its lane instead of stopping it abruptly or allowing it to go through. Segments are connected end to end to form a continuous run, so the line of barriers can share the energy of an impact.
In occupational safety, Jersey barriers are most important in highway and street construction, utility work, bridge repair and other roadway work zones, where workers are exposed to passing traffic. They are also used to protect excavations, separate pedestrians from equipment, control access at industrial sites and guard against vehicle intrusion at facilities and events.
Concrete barriers are heavy, rigid and, when properly installed and connected, capable of redirecting errant vehicles. Segments commonly run about 10 to 20 feet long and are often about 32 inches tall, though dimensions vary by state and manufacturer. Segments are joined by connection hardware such as pins and loops, steel plates or bolted connectors. Many variations exist, including the F-shape, which modifies the Jersey profile to reduce vehicle climb, and single-slope or constant-slope barriers.
Plastic barriers are made from polyethylene and are light enough to place by hand when empty, then filled with water or sometimes sand for added weight. They are faster and cheaper to deploy, are highly visible and cause less damage if struck at low speed. However, most water-filled barriers are intended for channelizing traffic or pedestrians, not for stopping or redirecting vehicles. Some systems can be crash tested as longitudinal barriers when they include internal steel frames or are installed exactly as tested, but they usually deflect much farther on impact than concrete barriers.
In the United States, temporary traffic control in work zones is governed by the Manual on Uniform Traffic Control Devices (MUTCD), particularly Part 6, which covers temporary traffic control. OSHA's construction standards for signs, signals and barricades in Subpart G (1926.200 to 1926.203) reference the MUTCD for traffic control devices. Highway agencies also typically require that barriers used to protect work zones meet crash testing criteria, such as those in the AASHTO Manual for Assessing Safety Hardware (MASH), and be installed according to state standard drawings.
The need for positive protection, meaning devices that prevent vehicles from entering the work space, is decided as part of the traffic control plan. Factors include traffic speed and volume, how long the work will last, how close workers are to traffic, and whether there are drop-offs or excavations next to the travel lane.
Where there is not enough room behind the barrier for normal deflection, such as next to a deep excavation, a bridge edge or a work crew, barriers can be pinned or anchored. Steel pins or anchor bolts are driven or drilled through holes in the barrier into the pavement or bridge deck to restrict movement. Pinning should follow the approved design, because the number and spacing of pins, pin length and pavement type all affect performance. Before drilling or driving pins, crews should check for buried utilities, bridge reinforcement, and drainage structures, and request an underground utility locate where needed.
Placing and removing barriers is itself high-risk work. Crews work close to live traffic, and segments are heavy loads lifted by cranes, forklifts or truck-mounted equipment.
A road crew was widening a two-lane highway shoulder and planned to excavate a trench about 5 feet deep next to the travel lane. The original plan used plastic water-filled barriers to separate traffic from the work area because they were easy to move as the work progressed. During the pre-job review, the project engineer noted that traffic speeds near the site were high and that the plastic barriers were not crash tested as longitudinal barriers. A vehicle striking them could push through into the trench where workers would be standing.
The contractor revised the traffic control plan to use connected precast concrete barriers with a flared, cushioned end facing traffic. Because the trench left little room for deflection, the barriers were pinned to the pavement following the state's standard drawing, after a utility locate confirmed no lines under the pin locations. Water-filled barriers were kept for low-speed areas at the site entrance to guide trucks. Two weeks later, a pickup truck struck the concrete barrier at night. The barrier redirected the truck back into the lane, and no workers were injured.
The sloped shape was developed and widely used by highway engineers in New Jersey. The name stuck and is now used for similar safety-shape barriers everywhere.
Not usually. Most water-filled barriers are designed for channelizing traffic and pedestrians. Unless a specific system has been crash tested and approved for the intended use, it should not be relied on to stop vehicles from entering a work zone.
Pinning limits how far the barrier moves when struck. It is used where there is not enough clear space behind the barrier, such as next to excavations, bridge edges or workers.
Yes. Segments are designed to work together as a continuous run. Unconnected segments can be pushed out of line individually, reducing protection and creating new hazards.
Part of SafetyIQ's EHS glossary: plain-English definitions of workplace health and safety terms.
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