CDL Vehicle Combination Practice Test

What is the definition of emergency controlled braking?

1. Gradually applying the brakes

2. Applying the brakes as hard as you can without locking the wheels

3. Using the emergency brake only

4. Pumping the brakes quickly

The correct answer is: Applying the brakes as hard as you can without locking the wheels

Emergency controlled braking is defined as applying the brakes as hard as possible without locking the wheels. This technique is crucial for maintaining control over a vehicle, especially in emergency situations where stopping quickly is necessary. When a driver applies the brakes with maximum force without allowing the wheels to lock, they achieve a balance between reducing speed and maintaining steering control. Locking the wheels can cause a loss of traction and steerability, which can lead to skidding, making it more challenging to navigate or avoid obstacles. Thus, controlled braking allows the driver to respond effectively in emergencies by maximizing braking force while still being able to maneuver the vehicle if needed. Other choices are not aligned with the definition of emergency controlled braking. For example, gradually applying the brakes does not provide the necessary urgency in critical situations, while using the emergency brake only is not advisable for immediate stopping and can sometimes lead to loss of vehicle control. Pumping the brakes quickly might not effectively apply enough stopping power needed and may also interrupt weight transfer that is crucial for optimized braking efficiency.