Heavy Duty Trailer Chocks for Safe Parking & Dock Loading

FMCSA requires at least one chock per commercial motor vehicle. Best practice is two chocks per trailer, placed on both sides of one axle. For tandem-axle trailers at loading docks, chock both rear tires on one side as a minimum. Many fleet safety programs require four chocks (both sides of both rear axles) for maximum security.

Yes. Air brakes can lose pressure over time, especially if the trailer is disconnected from the tractor. Chocks provide a mechanical backup that works regardless of brake condition. OSHA requires chocking at loading docks even when air brakes are set, and many insurance carriers require chocks as a condition of coverage.

For standard 22.5-inch semi-trailer tires, you need chocks at least 8 inches tall and 10 inches wide. The chock should contact roughly one-quarter of the tire height. For the common 295/75R22.5 tire (40-inch diameter), look for chocks rated for 40,000+ lbs per chock. Undersized chocks are dangerous because the tire can roll over them.

Rubber chocks are the industry standard: affordable, heavy enough to stay in place, and offer excellent grip on pavement. Urethane chocks weigh 30-40% less and resist chemicals better, making them preferred in food distribution and clean environments. For most commercial fleets, rubber delivers the best combination of price and performance.

Inspect chocks before each use for cracks, chunks missing, worn grip surfaces, or deformation. Replace immediately if damaged. Under normal use, quality rubber chocks last 3-5 years. Urethane chocks typically last longer (5-7 years). Aluminum chocks can last indefinitely with periodic inspection. Replace any chock that no longer sits flat or shows visible wear on the contact surface.

OSHA 1910.178(k)(1) and 1910.178(m)(7) require wheel chocks on trailers at loading docks whenever forklifts are used to enter or exit the trailer. Additionally, OSHA mandates that truck brakes be set and chocks placed before loading or unloading begins. Violations can result in fines exceeding $15,000 per occurrence. Many facilities add vehicle restraints alongside chocks for redundant safety.

Place both chocks on the same axle, one in front and one behind the tire, to prevent both forward and backward movement. This is more effective than one chock on each side. For maximum security at docks, chock both sides of the same rear axle (four chocks total, two per tire).

Standard flat-bottom rubber chocks are less effective on gravel, dirt, or uneven terrain because they cannot grip the loose surface. For off-road or gravel yard use, select chocks with cleated or serrated bases that dig into the surface. Aluminum chocks with serrated edges perform best on loose substrates. On steep grades, combine chocks with wheel restraints or dock locks.