Control delay is the component of delay that results from the type of control at the intersection; it is measured by comparison with the uncontrolled condition. It is the difference between the travel time that would have occurred in the absence of the intersection control, and the travel time that results because of the presence of the intersection control.

The definition of control delay is illustrated graphically above. While this illustration defines control delay for an approach to a stop-controlled intersection, the concept is equally applicable to signal-controlled intersection approaches.