What is the effect of driving at excessive speed in a curve?

• A. Increased risk of loss of control or rollover due to centrifugal force and weight transfer.
• B. Increased stability due to momentum.
• C. No effect on vehicle stability.
• D. Improves steering response.

Answer: (A)

When a vehicle travels through a curve, it must generate enough lateral (sideways) force to stay on the curved path. As speed increases, the necessary lateral force grows with the square of speed (v^2/r). The tires can only supply a certain amount of grip through friction with the road. If speed is excessive, the required lateral force exceeds what the tires can provide, causing the vehicle to slide or skid out of the curve. At the same time, inertia causes weight to shift to the outside of the curve, increasing load on the outer tires and reducing grip on the inner tires. This combination raises the risk of losing control or rolling over, especially in vehicles with a higher center of gravity. So the correct answer highlights the increased risk due to the outward “centrifugal” effect and weight transfer.

Momentum or inertia by itself does not make a vehicle more stable in a curve, no effect on stability is not accurate, and claiming steering becomes better at high speed is incorrect because grip limits and weight transfer can make steering less predictable.