Large commercial vehicles which have lost control in hilly terrain present a major challenge to engineers concerned with highway safety. The most common approach to this problem is the construction of truck emergency escape ramps, usually employing deepgravel arrester beds. In this approach, a separate lane is constructed off the main road. This lane, or ramp is typically one hundred to two hundred meters in length and surfaced with either rounded riverbed gravel or angular crushed gravel in depths varying from one to two meters. While these arrester beds are generally effective in bringing an out of-control truck to a stop, there are many serious drawbacks to their use. The Dragnet Vehicle Arresting Barrier has Vehicle Arresting Barrier has seen widespread use in the United States to safely stop passenger vehicles from intruding into perilous areas such as construction zones, open drawbridges, reversible traffic lanes, emergency road closures, etc. It is designed to stop errant vehicles with very low accelerations and minimal damage. The success of the Dragnes, led its designers to investigate the possibility of adapting it for use in emergency truck ramps. A series of development tests was performed and positively evaluated. (A)
Samenvatting