The CW13-1 ADVISORY SPEED plate may be used in conjunction with any construction warning sign to indicate the maximum safe speed for passenger cars around a curve or through a hazardous location. It shall not be used in conjunction with any sign other than a construction warning sign, nor shall it be used alone.

The CW13-1 plate shall always be mounted on the same post with, and immediately below, the construction warning sign to which it applies.

The CW13-1 plate is classed with the construction warning signs because, when used, it is in effect a part of a construction warning sign.