Crest Vertical Curves. Crest vertical curves on constant-width roadways approaching
the merging nose should be designed to provide sight distance consistent with the
design speed of the roadway. Crest vertical curves from the merging nose forward to a
point where pavement convergence ceases, and to the converging portion of an
approaching roadway where the number of lanes is being reduced in advance of the
nose, should be designed using stopping sight distance values 25 percent higher than
shown in Table 2.18. When design speeds differ on approaching roadways, the higher
of the two design speeds should be used in designing the crest vertical curve beyond
the merging nose.