A REVIEW OF THE DRAGNET VEHICLE ARRESTING SYSTEM AS APPLIED TO RUNAWAY TRUCK ESCAPE RAMPS. FINAL REPORT

The DRAGNET vehicle arresting system was reviewed for application in truck escape ramps. The Arizona Department of Transportation (ADOT) currently uses gravel arrestor beds to stop vehicles that lose braking power on sustained grades. Gravel arrestor beds have cost between one and two million dollars to build. The DRAGNET system was reviewed as a possible improvement over gravel arrestor beds, both in terms of cost and safety. Calculations were performed on a configuration of DRAGNETs to determine the stopping distance and deceleration for the ADOT arrestor bed design vehicle (80,000 lbs entering at 90 mph). A safety factor of two was applied to the kinetic energy of the incoming vehicle in all designs. Also, sand barrel arrays were recommended for the end of all DRAGNET truck escape ramps. Two other configurations in which the longitudinal spacing of the nets was varied were used with two additional vehicle weights, each entering at four different speeds, to construct a table of occupant impact velocity, ridedown decelerations, and distance traveled. The results of the evaluation showed that a DRAGNET system to stop the ADOT design vehicle with a maximum ridedown deceleration of .45 g's and a safety factor of two would require 25 net assemblies. ADOT has a gravel arrestor in the design phase that was used as a basis for an economic evaluation. A DRAGNET truck escape ramp would be 21% higher for first cost. The maintenance for a gravel arrestor bed is between $300 and $500 per entry while a DRAGNET system would cost between $50,700 and $97,500 per entry.

• Corporate Authors:

  Arizona Department of Transportation

  206 South 17th Avenue
  Phoenix, AZ  United States  85007

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • METCALF, D
• Publication Date: 1991-6

Media Info

• Pagination: 21 p.

Subject/Index Terms

• TRT Terms: Alternatives analysis; Arrester beds; Costs; Deceleration; Escape lanes; Gravel; Maintenance management; Stopping distances
• Uncontrolled Terms: Maintenance costs
• Old TRIS Terms: Dragnet vehicle arresting systems; Gravel arrestor beds; Initial cost; Runaway vehicles
• Subject Areas: Design; Finance; Highways; Safety and Human Factors; Terminals and Facilities; I85: Safety Devices used in Transport Infrastructure;

Filing Info

• Accession Number: 00619200
• Record Type: Publication
• Report/Paper Numbers: AZSP-9101
• Files: TRIS, USDOT, STATEDOT
• Created Date: Feb 29 1992 12:00AM