What is incident delay a result of?

Incident delay is primarily a result of incidents such as accidents. When an unexpected event, like a vehicle collision, occurs on a roadway, it can significantly disrupt the normal flow of traffic. This disruption may cause congestion as vehicles slow down or stop to navigate around the location of the incident. As a consequence, traffic volumes can build up behind the incident, leading to a delay that is specifically tied to the occurrence of that incident.

In contrast, standard traffic flow adjustments typically involve managing traffic under normal conditions, which would not be characterized as incident delays. Traffic enforcement actions may cause temporary delays, but they do not stem from incidents themselves. Routine maintenance operations can also lead to delays, but these are planned activities rather than unexpected incidents. Therefore, the connection between incidents like accidents and the resulting delays is what makes this choice the most accurate description of incident delay.