E 372 Hillside or Mountainous Terrain

Terrain in which the average grade is more than 5 percent is considered hillside or mountainous.

E 372.1 Undeveloped Land

The definition of undeveloped land given in Subsection E 371.1 applies here as well.

1. Terrain:
   1. In extremely steep or rugged terrain, the volume of earthwork as well as the maximum and minimum grade percentages are the limiting factors.
   2. In rolling terrain, the maximum and minimum percentages of grade will usually determine the grade and alignment, with lesser consideration given to earthwork.
2. Highway Design Standards:
   1. In steep terrain, for a given street or highway and design speed designation the highway design standards should be met. Usually in this type of terrain the design speed should be lowered to meet these standards.
   2. In rolling terrain, the normal design speed and the highway design standards control.
3. Existing Improvements:
   1. In steep terrain, meeting the property is relatively unimportant.
   2. In rolling terrain, future development of the abutting property should be considered.
   3. Drainage may be an important consideration if extensive sump areas or watercourses are encountered.

E 372.2 Developed Land:

The definition of developed land given in Subsection E 371.2 applies here as well.

1. Terrain:
   1. In mountainous areas, property development is much less intensified than in other types of terrain. In general, except for an occasional driveway to be met, the design controls are similar in mountainous areas for developed as well as undeveloped land.
   2. In rolling terrain, depending on the degree of development, a certain amount of earthwork has been or will be done in the development process. Therefore, in general, earthwork is not necessarily a critical factor. The ruling design factor in grade location will then be the maximum and minimum grades.
2. The street and highway design and maximum speed standards should be met.
3. The existing improvements should be joined.
4. Drainage is generally a problem only regarding directing surface flow and in encountering an occasional sump condition or watercourse.