Which scenario most increases rollover risk when operating a tall vehicle?

• A. Taking a curve at excessive speed.
• B. Descending a straight grade at low speed.
• C. Driving in a straight line.
• D. Parking at a scene.

Answer: (A)

When a tall vehicle turns, lateral forces push the vehicle outward. With a high center of gravity, that outward push causes more body roll and can lift a tire, increasing the chance of a rollover. So entering a curve at excessive speed creates the largest combination of speed, steering input, and weight transfer that can lead to a rollover.

Descending a straight grade at low speed mainly brings about braking and gravity along the direction of travel, not the sideways force that causes rollover, so the risk is much lower. Driving in a straight line is inherently more stable for a tall vehicle, and parking at a scene involves little to no dynamic rollover force if the vehicle is stationary and properly secured.