What is the stopping distance at 40 mph?

The stopping distance at 40 mph is 120 feet, which accounts for the time it takes to perceive a hazard, react to it, and then bring the vehicle to a stop. Stopping distance typically comprises two components: reaction distance and braking distance.

At 40 mph, a driver's reaction time can range from 1.5 to 2 seconds, during which the vehicle continues to travel forward. The distance covered during this time, known as the reaction distance, is important to consider.

Once the brakes are applied, the braking distance increases with speed due to the need for greater force to decelerate a vehicle that's travelling faster. At 40 mph, the combination of reaction distance and braking distance leads to an overall stopping distance of approximately 120 feet, which is a practical figure that informs drivers of the necessary space they should maintain between themselves and other vehicles, especially in varied driving conditions such as wet roads or heavy traffic.

Understanding this distance can help drivers make safer decisions, particularly regarding following distances and safe stopping practices, thereby contributing to overall road safety.