What generally causes rear-wheel braking skids?

Rear-wheel braking skids primarily occur when the drive wheels lock up during braking, which is why the correct response identifies this factor. When the rear drive wheels are locked, they lose traction and can no longer maintain control over the vehicle's path, leading to skidding. This situation is especially common in vehicles with rear-wheel drive but can happen in any vehicle under conditions where braking force overwhelms the available traction.

Excessive speed can contribute to skidding, but it does not directly cause rear-wheel locking. While a lack of traction on the front tires can lead to handling issues, it is not the primary cause of rear-wheel skids. Overloading the vehicle can also affect overall traction and handling, but the immediate cause of a rear-wheel skid is the locking of the drive wheels during braking. Understanding these dynamics is crucial for safe vehicle operation and effective braking techniques.