Which of the following is a factor that may cause a forklift to tip over sideways?

• A. Brakes fail
• B. Horn use
• C. Smooth surface
• D. Uneven surfaces

Answer: (D)

Forklift stability relies on keeping the combined center of gravity within the wheelbase and the base of support. An uneven surface disrupts that balance by creating different grip and height under each wheel, which can tilt the machine toward one side. If the ground is uneven or has holes, ruts, or slopes, the load—especially when raised or off-center—can shift laterally and push the center of gravity toward the outer edge, increasing the risk of tipping sideways. Brakes failing, horn use, or a smooth surface don’t inherently create that sideward tipping tendency; brakes failing affects control, horn use is irrelevant to stability, and a smooth surface actually reduces tipping risk.