UNIT 6 VEHICLE HANDLING THE EFFECT OF CONDITIONS

Traction What is traction? Traction is the contact between the tires and the road surface on which it is moving, without which the object cannot move. Traction is affected by:  Weather: ice, snow, water on the road surface  Tire tread and pressure and weight of the vehicle  Material of the road surface Without traction:  Your vehicle cannot move  You cannot accelerate or decelerate  You cannot maintain control on turns Low traction means you will need more space to stop! Slide 6.1

Friction Friction occurs whenever two objects rub against each other; in driving, your wheels move against the road surface. Friction occurs at all times, even when you are not accelerating. Friction is reduced:  By ice, snow, water on the road surface  By low tire tread  By some materials of the road surface Slide 6.2

Skidding and Sliding What is skidding? A skid happens when your wheels slide out of control on a slippery surface. Skids can involve the front, rear or all four wheels. What causes skidding?  driving too fast for road or traffic conditions  sudden, hard braking  going too fast around a corner  accelerating too quickly Slide 6.3

Skidding and Sliding If you skid…Look where you want the vehicle to go and steer in that direction. If you are on ice, skidding in a straight line, step on the clutch or shift to neutral. Preventing a skid when you must brake sharply:  Threshold braking — Brake as hard as you can. If you feel any of the wheels locking up, release the brake pressure slightly and re-apply. Continue braking this way until you have brought the vehicle to a complete stop.  Anti-lock brakes — Anti-lock brake systems give you maximum threshold stop automatically. Slide 6.4