When estimating travel time, beyond distance and speed, you should adjust for what?

• A. Weather
• B. Road maintenance
• C. Traffic density
• D. Delays such as traffic signals

Answer: (D)

When estimating travel time, the time spent waiting at intersections due to traffic signals can dominate the overall minutes you’ll add on top of distance and speed. Even if you drive at a steady speed and cover the planned distance, red lights, green-light delays, and the time needed to decelerate and accelerate around crossings create additional waiting time. These signal-related delays accumulate across many intersections and can significantly extend the trip, especially in urban areas. So, you should adjust for delays such as traffic signals because they represent predictable, routine hold-ups that aren’t captured by distance divided by speed alone. Weather, road maintenance, and traffic density affect speed and flow, but the explicit adjustment for travel time beyond distance and speed is the delays caused by traffic signals.