The main cause of skidding is the loss of traction between the vehicle's tires and the road surface. This loss of grip can occur due to various factors, the most common being:

• Wet, icy, or slippery road conditions that reduce friction.
• Excessive speed for the road or weather conditions.
• Sudden braking or sharp steering movements.
• Worn-out or bald tires that can't grip the road effectively.
• Over-acceleration or over-braking leading to wheel spin or lock-up.

In essence, skidding happens when the tires cannot maintain enough friction to match the speed or direction changes of the vehicle, causing it to slide uncontrollably.