What should you do if your brakes fail while driving?

If your brakes fail while driving, using the handbrake and downshifting is the most effective action to take. Engaging the handbrake provides an additional means to slow the vehicle down, as it activates the rear brakes. This is particularly important when there’s a complete loss of brake function. Downshifting decreases the vehicle's speed through engine braking, which can help in controlling the car's descent and reducing velocity even further.

The combination of these two actions allows for a gradual decrease in speed rather than a sudden stop, which can lead to loss of control or skidding. It’s crucial to maintain vehicle control while bringing the car to a stop safely, and this approach aids in that regard.

In situations where the brakes have failed, steering towards open spaces or away from crowded areas—like sidewalks or other obstacles—would be important, but that action alone doesn't address how to slow down the vehicle effectively. Accelerating or hitting the gas to stop quickly is not a safe strategy in this scenario, as it can lead to an increased risk of collision or loss of control over the vehicle.