Arkansas Commercial Driver License (CDL) Practice Test

What is the greatest braking effect achieved near?

1. High speeds

2. Transmission in high gears

3. Near governed RPMs

4. Steep inclines

The correct answer is: High speeds

The greatest braking effect is achieved near governed RPMs, which is the correct context in this scenario. When a vehicle is operating near its governed RPMs, the engine is functioning at its optimal performance level, allowing for better control over the vehicle’s speed. This means that the engine can more effectively engage in engine braking, which significantly enhances the overall braking power and reduces the reliance on the service brakes. In this context, the other factors mentioned may not contribute as effectively to braking. High speeds might create more momentum, which requires larger braking forces and can lead to longer stopping distances. Transmission in high gears may result in reduced engine braking capacity, as lower gears typically provide better leverage for slowing down. Lastly, while steep inclines may add to the challenges of braking, they typically do not contribute to maximum braking effectiveness as effectively as being near governed RPMs does. Therefore, engaging the engine effectively while close to governed RPMs is the key to achieving the greatest braking effect.