What is the typical startup lost time at an intersection?

• A. 1 second
• B. 2 seconds
• C. 3 seconds
• D. 5 seconds

Answer: (B)

The typical startup lost time at an intersection is considered to be approximately 2 seconds. This time accounts for the delay experienced by vehicles when a traffic signal changes, and drivers begin to move from a stopped position.

This time reflects the natural reaction time required for drivers to perceive the signal change, release the brake, and then accelerate before they reach a speed where they can effectively merge into the flow of traffic. Understanding this aspect of traffic flow allows for better traffic signal timing optimization and can help in modeling traffic operations at intersections.

In practice, while different intersections may exhibit slight variations in startup lost time due to factors such as vehicle type or driver attentiveness, 2 seconds is widely accepted as a standard metric in transportation engineering for evaluating delays at signals and improving overall traffic management.