Final answer:
Rear-wheel ABS on light trucks prevents the rear wheels from locking up during heavy braking, which helps to maintain traction and directional control, especially on slippery surfaces. This enhances vehicle stability and steerability.
Step-by-step explanation:
The main answer to the question 'Rear-wheel ABS (only on some light trucks) prevents...' is that rear-wheel ABS, which stands for Anti-Lock Braking System, prevents the rear wheels from locking up during a sudden stop or under heavy braking conditions. When the wheels lock up, there is a loss of traction and directional control which can lead to skidding. ABS works by rapidly pulsing the brakes on and off to prevent skidding and maintain steerability. This is especially helpful in maintaining vehicle stability and directional control on slippery surfaces such as ice, snow, or wet pavement.
For light trucks with rear-wheel ABS, the system is specifically designed to manage the rear wheels, which is essential because the rear part of a truck can often become light during unloaded or light cargo conditions, increasing the risk of the rear end losing traction. The explanation for why this stability is essential can be found in the physics of vehicle dynamics, where the weight distribution and the force of friction between the tires and the road surface play critical roles in vehicle control.