The effect of shoulder width and type on rural traffic safety and operations.

The first section of the report discusses the functions of shoulders and considers the types of shoulder design which have been used or suggested. The second section of the report is a review of the literature on the relationship between accidents and shoulder design, the usage of shoulders and the effect of shoulder design on traffic operations. Most of the literature reviewed is American and much is over 20 years old. The safety benefits of shoulders resulted mainly from their function in providing a recovery area, which was best achieved by paved shoulders, particularly as gravel shoulders could increase loss of control.