How does road surface condition affect braking distance?

• A. Dry pavement provides the longest stopping distance
• B. Wet, icy, or uneven surfaces increase stopping distance and reduce tire grip
• C. Surface conditions have no effect on braking
• D. Brakes perform best on wet surfaces

Answer: (B)

When road surface condition changes, the key factor is how much grip the tires can maintain on the road. Dry pavement gives the highest friction, so tires can convert braking force into stopping force most effectively, producing the shortest stopping distance. On wet, icy, or snowy surfaces the friction is much lower, and water or ice acts like a lubricant, making tires more prone to slide instead of grip. This reduces braking efficiency and lengthens the distance needed to stop. Uneven surfaces introduce irregular grip—potholes, ruts, or gravel disrupt traction and can cause tires to lose contact or slip, further increasing stopping distance. In practice, this means braking distances grow on slick or uneven roads, so slow down and leave more following distance when conditions are wet, icy, or rough.