“K-rail” is simply the California-specific term to describe what the rest of the country refers to as “Jersey barriers.” Both terms refer to the same barrier design.

F-Shape barriers have the same 3-inch-high base as a K-rail barrier, but they feature a side that slopes 10 inches above the pavement rather than the 13-inch side slope of the K-rail, which allows them to better absorb impacts from smaller vehicles.

A K-rail is a modular concrete or plastic traffic barrier used to separate lanes of traffic. They are commonly used to reroute vehicular traffic during roadworks and delineate the construction zone. Other uses for k-rails include site security, flood defense, edge protection and temporary military barriers.

The K-rail that has become the standard within California consists of 6.1-m (20-ft) long sections with pin and loop connections, each weighing approximately 3630 kg (8000 lbs).