Development of a three cable guide rail system and other guide rail tests, 1967-1968. Paper presented at the 49th Annual Meeting of the Highway Research Board HRB, Washington, D.C., 1970.

A series of impact tests were carried out on guide rail systems for rural highways. The tests confirmed that an effective post and cable system could be developed and that it would likely take the form of three ½ in. steel cables mounted on 6 in. cedar posts spaced at 12 ft. centers. A special provision would be required to facilitate cable tensioning and anchoring.