Mainline crest vertical curves in the vicinity of ramp terminals should be designed using stopping sight distance values 25 percent higher than the design speed value from Table 2.18. Where a crest vertical curve occurs on an exit ramp at or near the nose, the crest vertical curve should be designed using the “upper-range” design speeds of Table 2.28.
2.5.2 Ramp At-Grade Intersections
Ramp at-grade intersections are designed using many of the same criteria as outlined in Art. 2.4.1. However, one of the basic differences is the one-way nature of ramps and the fact that most traffic at ramp intersections is turning. Figure 2.44 shows the design of a typical uncurbed ramp intersection. Curbed returns are normally used in urban areas where space is more restricted.
