Abstract:
The Forest Service has an integrated system of computer programs for design of roads, including low-volume roads. This system is known as the Forest Service road design system. System calculations begin with initial traverse input and end with construction quantities. This paper briefly describes each program. Several programs that are felt to be unique to this system are discussed in more detail. The designer's aid program outputs information for the designer to establish a horizontal alignment, based on a trial grade and template information. The roadway template and slope selection programs allow the designer to define his template in terms of width, curve widening, superelevation criteria, and turnouts for shoulder-to- shoulder dimensions and variable slope criteria for cut and fill slopes, based on depth of cut and fill. The earthwork adjustment program provides a quantity defined as unit mass, the amount of mass change that would result from lowering or raising an existing vertical point of intersection elevation 1 ft (0.3 m). Unit mass is supplied to the designer for use in manual adjustments, or an option in the program will automatically use the unit mass and perform another earthwork run.
Supplemental Notes:
Proceedings of a work shop held June 16-19, 1975, in Boise, Idaho by the Transportation Research Board.
