A runaway truck ramp on the A7 in Germany
A runaway truck ramp on the A7 in Germany

A runaway truck ramp, runaway truck lane, escape lane, emergency escape ramp, or truck arrester bed is a traffic device that enables vehicles which are having braking problems to safely stop. It is typically a long, sand- or gravel-filled lane connected to a steep downhill grade section of a main road, and is designed to accommodate large trucks or buses. It allows a moving vehicle's kinetic energy to be dissipated gradually in a controlled and relatively harmless way, helping the operator stop it safely.

Design

Emergency escape ramps are usually located in mountainous areas which cause high construction costs and present difficult site selection.[1] A ramp may cost US$1 million.[2] Designs include:

Location

Emergency escape ramps are usually located on steep, sustained grades, as in mountainous areas.[1] Long descending grades can allow high vehicle speeds to be reached, and truck brakes can overheat and fail through extensive use. The ramps are often built before a critical change in the radius of curvature of the road, or before a place that may require the vehicle to stop, such as before an intersection in a populated area.[3] The placement criteria can vary from one region/country to another.

Gallery

See also

References

  1. ^ a b c DOT Arizona (May–June 1993). "Full-Scale Arrester Bed Testing Leads to More Cost-Effective Design" (PDF). TR News (166): 20–21. Retrieved 2006-07-23.
  2. ^ US 93 Hoover Dam Bypass Project (NV,AZ): Environmental Impact Statement. Federal Highway Administration. 2001. p. B-8.
  3. ^ a b c Design Manual - Auxiliary Lanes (PDF). Washington State Department of Transportation. May 2006. Chapter 1010, pp. 4–5. Archived from the original (PDF) on 2005-09-24.
  4. ^ "Highway 11 Runaway Truck Ramp". Ontario Ministry of Transportation. 2009-06-26. Archived from the original on 2012-05-06. Retrieved 2016-11-18.
  5. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2011-09-05. Retrieved 2011-12-17.((cite web)): CS1 maint: archived copy as title (link)