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. Skids caused by acceleration usually happen on ice or snow. They can be easily stopped by taking your foot off the accelerator. Rear wheel braking skids occur when the rear drive wheels lock. With vehicles towing trailers, a drive-wheel skid can let the trailer push the towing vehicle sideways, causing a sudden jackknife.