What is the minimum reduction in roadway capacity when a crash occurs on the shoulder?

When a crash occurs on the shoulder of a roadway, it can significantly impact the roadway's capacity, even though the incident itself is not blocking the travel lanes. The correct answer indicates a minimum reduction of 17% in roadway capacity under these circumstances.

This reduction accounts for factors such as motorists being distracted by the incident, changes in travel behavior as vehicles maneuver around the area, and a general decrease in speed due to the presence of emergency vehicles and the potential for rubbernecking. These elements collectively contribute to a reduction in effective roadway capacity, as the flow of traffic is altered.

It's important to understand that although the shoulder is intended for emergencies, the presence of a crash can still lead to safer and more cautious driving behaviors by other drivers. This reduction figure emphasizes the need for effective incident management to minimize disruptions on the roadway and ensure a swift return to normal traffic conditions.