What should you do if your brakes fail while driving?

Answer: A — Shift to a lower gear and use emergency brakes

If your brakes fail while driving, shifting to a lower gear and using the emergency brakes is the most effective way to regain control of the vehicle. This action helps slow the car down gradually by using the engine's resistance as well as the additional stopping power provided by the emergency brakes. Engaging a lower gear allows the vehicle’s engine to help decelerate, which is crucial for maintaining control during a braking failure. Continuously riding the brakes could lead to overheating and further brake failure, while stopping immediately on the road is dangerous as it may cause a collision with vehicles following behind. Using the horn might alert other drivers, but it does not address the critical issue of controlling the vehicle or stopping it safely. Therefore, the best course of action in the event of brake failure is to shift to a lower gear and use the emergency brakes to reduce speed and come to a safer stop.