A skid happens whenever the tires lose their grip on the road. Braking too hard and locking up the wheels.
Skids also can occur when using the speed retarder when the road is slippery.
Turning the wheels more sharply than the vehicle can turn. Supplying too much power to the drive wheels, causing them to spin. Driving Too Fast. Most serious skids result from driving too fast for road conditions. By far the most common skid is one in which the rear wheels lose traction through excessive braking or acceleration.