This section is concerned with the design of the slopes, ditches, parallel channels, and
interchange grading. It incorporates into the roadside design the concepts of vehicular
safety developed through dynamic testing. Designers are urged to consider flat
foreslopes and backslopes, wide gentle ditch sections, and elimination of barriers.
Slopes. Several combinations of slopes and ditch sections may be used in the grading
of a project. Details and use of these combinations are discussed in subsequent
paragraphs. In general, slopes should be made as flat as possible to minimize the
necessity for barrier protection and to maximize the opportunity for a driver to recover