An air brake-equipped vehicle traveling at a speed of 55 mph under ideal driving conditions will need approximately __ to come to a complete stop.
Answers
100 feet
250 feet
300 feet
450 feet
The Correct Answer and Explanation is :
The correct answer is 450 feet.
In ideal driving conditions, an air brake-equipped vehicle requires significantly more distance to stop compared to a vehicle with conventional braking systems. The braking distance depends on several factors such as the vehicle’s speed, the efficiency of the braking system, road conditions, and the weight of the vehicle.
For an air brake system, the stopping distance can be broken into two components:
- Perception Distance: This is the distance the vehicle travels while the driver is recognizing the need to stop and making the decision to apply the brakes. This distance depends on the driver’s reaction time, typically around 1.5 seconds, and at 55 mph, the vehicle would cover approximately 121 feet before the brakes are even applied.
- Braking Distance: After the driver applies the brakes, the vehicle continues to decelerate until it comes to a stop. For air-braked vehicles, this distance is typically much longer than for vehicles with hydraulic brakes. At 55 mph, the braking distance alone for an air brake-equipped vehicle can be up to 300 feet. This distance is influenced by the time it takes for air to travel through the brake lines and the additional weight of the vehicle, which affects how quickly the vehicle slows down.
When combined, the perception and braking distances at 55 mph total around 450 feet. This longer stopping distance is especially important for drivers of large commercial vehicles, like trucks or buses, who must maintain a larger following distance and plan ahead for stopping to avoid collisions. In contrast, lighter vehicles with more responsive braking systems can stop in much shorter distances.