Figure 2.48 shows a reversed curve

Figure 2.48 shows a reversed curve design (types A and B), a tapered design (type C),
and a design for a transition on a curve (type D) for achieving a four-lane divided to
two-lane transition. The pavement transition should be located in an area where it can
easily be seen. Intersections or drives should be avoided in the transition area.
Vertical or horizontal curves should provide preferred stopping sight distance. Reverse
curve transitions should normally be used for median widths of 20 ft (6 m) or wider.
Taper lengths are based on the design speed of the mainline and are calculated from
Eq. (2.5).