The horizontal alignment of a roadway should be designed to provide motorists with a
facility for driving in a safe and comfortable manner. Adequate stopping sight distance
should be furnished. Also, changes in direction should be accompanied by the use of
curves and superelevation when appropriate in accordance with established guidelines.
Some changes in alignment are slight and may not require curvature. Table 2.5 lists the
maximum deflection angle which may be permitted without the use of a horizontal
curve for each design speed shown. It is assumed that a motorist can easily negotiate
the change in direction and maintain control over the vehicle without leaving the lane.