Performance of a gravel-bed truck-arrestor system.

A truck-arrestor system consisting of a 528-ft long bed of 2-ft deep screened gravel, backed up by an array of 88 sand-filled plastic barrels, was constructed on a steep downgrade where geometric restrictions precluded building a conventional uphill escape lane. Three trial runs at speeds of 21, 41, and 56 mph with a 37,000-lb dump truck demonstrated the gravel bed's capability to stop runaway vehicles. Decelerations experienced in these tests were similar to those in panic stops on dry pavement.