What does control delay consist of?

Control delay specifically refers to the delay that is directly associated with the control devices used to manage traffic flow, such as traffic signals or stop signs. This type of delay occurs because vehicles must stop or yield due to these traffic control measures. It is distinct from other types of delays that may occur in a traffic system, such as those caused by geometric factors (like road design) or queueing effects (like the buildup of vehicles waiting to pass through an intersection).

By isolating control delay to only the operations of traffic control facilities, it provides a clearer understanding of how these elements impact traffic flow. This is important for traffic engineers and planners who wish to evaluate the effectiveness of control devices and make informed decisions about adjustments or improvements to traffic signal timing, for instance.

In contrast, the other options encompass broader definitions of delay that include factors outside the basic influence of control measures. This delineation emphasizes the specific nature of control delay as critical for evaluating the efficiency of traffic management strategies.