How to Properly Use Wheel Chocks? | Stop Any Roll

Wheel chocks are the last line of defense between your vehicle and an expensive, dangerous roll. Set the brake, stop the vehicle completely, and only then place chocks. The steps are simple, but skipping one—like chocking before the brake, or using a rock instead of a real chock—defeats the entire purpose. When you get ready to buy, our tested roundup of the best heavy duty wheel chocks separates the options that hold on steep grades from the ones that slide.

How Do You Position Chocks Correctly?

Positioning depends entirely on the slope and the direction the vehicle would roll if the brakes failed. Get this wrong and the chock becomes a speed bump rather than a stop.

The National Ready Mixed Concrete Association’s guide adds that chocks should sit centered and square with the tire, placed snugly against the tread, and positioned on the downhill side of the vehicle’s center of gravity.

What Is the Right Step Order?

Sequence matters because a chock cannot stop a vehicle that is already moving. The vehicle must be at a complete standstill before anything touches the tires.

1. Bring the vehicle to a full stop on a solid, level surface whenever possible.
2. Set the parking brake and put the transmission in park or in gear.
3. Place the chocks centered and square against the tire tread on the downhill side of the roll direction.

Usda ARS safety guidance is blunt about materials: use specially designed truck wheel chocks of appropriate size. Lumber, cinder blocks, rocks, and other improvised items are not acceptable substitutes—they crack, slide, or crush under load.

Which Vehicles and Situations Require Chocks?

Any vehicle that could roll needs chocks: passenger cars, trailers, trucks, bucket trucks, and service vehicles all qualify. Trailer-specific guidance says to chock the trailer wheels before disconnecting from the tow vehicle. For a towable generator or unhitched trailer, ACT Safe recommends chocking both sides of one wheel.

OSHA’s powered industrial truck rule (29 CFR 1910.178(k)(1)) sets the legal floor for highway trucks in that context: set the brakes and place wheel chocks under the rear wheels to prevent rolling while the vehicle is boarded. The same logic applies to any vehicle being serviced or left parked on a grade.

One consumer guide notes wheel chocks work best on solid, level ground and warns more chocks may be needed on slopes or with heavier vehicles. On soft ground, larger or additional chocks help spread the load. Match the chock to the vehicle’s weight and wheel diameter; a chock sized for a compact car will not hold a loaded trailer.

Frequently Asked Questions

Should I chock one wheel or both wheels?

Use at least two chocks, one on each side of the same wheel on level ground. For heavy vehicles or steep slopes, add more chocks on additional wheels for extra security.

Can I use wood or rocks instead of wheel chocks?

No. Rugged wood, cinder blocks, and rocks are not designed for the job and can crack, slide, or crush under vehicle weight. Wheel chocks are shaped with a curved face that matches the tire and a base that grips the ground. Using improvised items creates a false sense of safety and is explicitly discouraged by safety guidance.

How do I know if my wheel chocks are worn out?

Inspect chocks regularly for cracks, deterioration, or worn gripping surfaces. Replace any chock that shows significant damage, especially if it has been used on rough ground or exposed to extreme temperatures. A chock with a smooth or cracked base loses its grip and becomes unreliable.

Check chocks for cracks before each use, replace damaged units, and inspect for wear regularly. On ice or snow, clear the area so the chock can seat securely; a chock sitting on packed snow will slide with the vehicle. These simple habits keep a basic safety device reliable for years.