Over the last 10 years passenger cars have become smaller, and the percentage of smaller cars in the traffic stream nation-wide, has increased dramatically, while trucks have become heavier and longer. Median barriers, like most other roadside hardware, were developed and installed before these changes in traffic composition started. Concern has been expressed that current median barriers used on the nation's highways may prove to be inadequate and that this fact may lead to higher severity rates of injuries and fatalities. Based on an extensive literature review the following recommendations are made:
The fleet size composition of passenger cars and the weight size range of heavy vehicles using the highway system has changed over the last 10 years. However, without specifics regarding individual site configuration and corresponding accident data, it is not possible to generalize what action should be taken on a state-wide basis. Obviously, action may be needed after due evaluation of a specific site based on cross median accident data.