What is a common cause of brake failures and downhill runaway crashes?

Poor speed control is a common cause of brake failures and downhill runaway crashes because it can lead to situations where the driver is unable to respond adequately to the required speed adjustments. When a driver is descending a steep hill, for instance, maintaining control over the vehicle's speed is crucial. If the speed is not adequately managed, the brakes can become overworked as they attempt to compensate for the increasing momentum of the vehicle. This extended use of the brakes, especially if they are already in a weakened condition, can lead to overheating and potential brake failure.

Moreover, when speed is not controlled effectively, the risk of losing control of the vehicle is heightened, potentially resulting in a downhill runaway situation where the driver can no longer stop the vehicle in a safe manner. Therefore, ensuring proper speed control is essential for safe driving, particularly in situations that involve steep grades or heavy braking.