Since 2003, the Texas Department of Transportation (TxDOT) has embarked on an aggressive campaign to install median barriers to prevent cross-median crashes on freeway facilities statewide. In the few years prior to 2003, virtually all fatalities on interstate facilities (96 percent) were the result of cross-median crashes. TxDOT used special safety funding to accelerate projects and decided to primarily implement high-tension cable/wire rope median barrier systems in lieu of concrete so that more roadway miles could be protected. This report documents the performance evaluation of various cable barrier systems in Texas. The research evaluated TxDOT’s experience with cable barrier systems by analyzing installation cost, recurring maintenance costs and experiences, crash history before and after implementation, and field performance. Some of the key findings include: From a capital cost and life-cycle cost perspective, cable barrier is an attractive option compared to concrete median barrier; There has been a lack of coordination between TxDOT and emergency responders during the project planning and maintenance phases of cable barrier system projects; Maintenance costs and personnel requirements for cable barrier systems can be substantial and constrained maintenance budgets and personnel availability for frequent repair needs are issues; Cable barriers are performing extremely well and have had very few cases of penetration unless there were nonstandard impact conditions. Researchers believe that the cable barriers are functioning according to their intended design and are restraining vehicles that impact them in fashions similar to NCHRP 350 crash-testing guidelines; The installation of cable barriers has produced significant benefits with a reduction of 18 fatalities and 26 incapacitating injuries in the first full year. This reduction equates to an almost $46 million economic benefit based on current crash cost values used in evaluation of projects for safety funding; Due to problems experienced in Texas and other states, soil conditions should be considered as part of the project development process for cable barrier system installations. (Author/publisher)
Samenvatting