What action should a driver avoid when traveling down a hill?

Coasting with the gears in neutral is an action that a driver should avoid when traveling down a hill because it reduces the driver's control over the vehicle. When a car is in neutral, the driver loses the ability to use the engine's braking power, which is essential for managing speed on a downhill slope. Using engine braking helps to maintain a safe speed and can prevent overheating of the brakes, which can occur when relying solely on braking to control descent.

Maintaining a controlled speed using the appropriate gears allows for better handling of the vehicle and makes it easier to respond to any unexpected situations, such as other vehicles or obstacles. Therefore, keeping the vehicle in gear while descending a hill is crucial for safety.