Illinois CDL Practice Exam

When encountering a steep downhill grade, using engine braking or lower gears is the most effective and safe action for a driver to take. This technique involves downshifting to a lower gear, which allows the vehicle's engine to slow down the vehicle's speed without the excessive use of the brakes. By relying on engine braking, drivers can maintain better control of their vehicle and prevent brake overheating. Brake fade can occur if brakes are applied continuously on a downhill slope, leading to decreased braking effectiveness and an increased risk of losing control.

Lower gears provide additional resistance from the engine when going downhill, thus helping to manage the speed more safely. This method not only enhances safety but also prolongs the life of the braking system. In steep downhill situations, maintaining control is critical, and utilizing the engine's resistance rather than relying solely on brakes is a fundamental principle of safe driving.