Interstate highway shoulder use study in South Dakota.

The interstate highway shoulder use study was initiated in may 1963, to collect factual data on the use of shoulder areas for parking purposes on a controlled-access highway facility. Knowledge of shoulder usage can be utilized by the highway engineer when selecting a roadway design and when planning the size and distribution of safety rest areas along the highway. The information is also of interest to enforcement groups who are responsible for the maintenance and control of traffic on the interstate highway system.