Citation

Rowan NJ, Marquis E, Johnson J. ITE J. 1977; 47(5): 38-42.

Copyright

(Copyright © 1977, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

Four steps are outlined that should be followed to improve roadway safety through redesign, as well as the state of the art concerning various devices and methods necessary to apply them properly. The priority approach for implementing a safe roadside design is given: all hazardous elements that are not essential to the operations of the roadway should be eliminated, such as unnecessary signs, trees, obsolete culvert headwalls, and other physical objects. Objectives that can perform their functions equally well at a greater distance from the edge of a traveled way should be relocated. Objectives that cannot be eliminated or relocated but are essential elements within 30 feet of the roadway should be made breakaway, such as roadside signs and luminaire supports adjacent to the roadway. Where none of the these previous steps apply, attenuation devices, known as crash cusions have been developed to protect the driver. Their principal objective is to reduce the speed of the vehicle uniformly over time and distance. A discussion of the state of the art concerning various devices and methods to improve roadway safety through redesign include: Breakaway devices, crach cushions, roadside barriers, median barriers, and the development of guidelines for selecting, locating and designing traffic barriers.