On most major highways, there are tracts of road with
medians, and other tracts of road without medians. The lack of a median between lanes of oncoming traffic is a serious
safety concern, and requires a
solution. Enter the Median Barrier.
It is not clear where or when the first concrete median barriers were made and/or used, but they go on record in the mid-1940s as being used on US-99 on the descent from the Tehachapi Mountains in the central valley south of Bakersfield, CA. The reason for the development was, as noted above, to reduce the number of out-of-control trucks penetrating the barrier, and to eliminate the need for costly and dangerous median maintenance in areas with narrow medians (or none). Of course, these issues are still with us today.
There are 5 different types of Median Barriers both in use and in obsoletion. They are:
Ontario Tall-Wall Barrier
F-Shape Barrier
(I read that there are actually 6 distinct types, but could not find information on the illusive 6th type)
Each barrier fills a particular niche role in highway safety, but there is a strong move for F-Shape Barriers. Each linear foot of concrete median barrier costs two to three times as much as a steel guardrail median barrier, but provides significantly more protection.
The various barriers are used for temporary and permanent applications.