Among the various
Median Barrier designs, the GM Barrier was one of the early designs to be used in
America. The concrete barrier was developed by
General Motors and the
Texas Transportation Institute in the early 1970s. It is similar in appearance to the New
Jersey Barrier (NJB), but is clearly fatter. The
slope breakpoint is also approximately 3 inches higher than the NJB. The GM Barrier was
designed, not
evolved like other Median Barriers, by crash testing. The barrier was larger than those used today, mostly because cars were larger
back then.
The GM Barrier was used in Virginia until the late 1970s or early 1980s. The Capital Beltway widening project of 1974-1977 also used the GM Barrier. The Shirley Highway reconstruction from King Street to the Potomac River used it in 1969-1975, and several miles of the I-95 in South Richmond used the GM Barrier when the road was widened in 1974-1978.
Today, the GM Barrier is considered to be obsolete, and has been replaced with the New Jersey Barrier, the Constant-Slope Barrier, or the new trend, the F-Shape Barrier.