CMV Law: Tire Requirements

Tires: Overview

The concept that damaged, worn, or defective tires, or proper tires overloaded by the motor carrier, may fail is not a novel one. However, the regulations do include some requirements and exceptions that may come into play in a case.

CMV Tires

Under subpart C of part 393, motor carriers and drivers must observe the following rules with respect to the tires used on commercial motor vehicles:

1. No motor vehicle shall be operated on any tire which:

  • has body ply or belt material exposed through the tread or sidewall
  • has any tread or sidewall separation
  • is flat or has an audible leak
  • has a cut to the extent that the ply or belt material is exposed

2. Any tire on the front axle of a bus, truck or truck tractor must have at least 4/32 of an inch depth when measured at any point of a major tread groove.

3. Other tires must have at least 2/32 of an inch of tread groove when measured in a major tread groove.

4. No bus shall be operated with regrooved, recapped or retreaded tires on the front wheels.

5. A regrooved tire with a load-carrying capacity of 4,920 pounds or more shall not be used on the front wheels of a truck or truck tractor.

6. No motor vehicle shall be operated with tires that carry a weight greater than that marked on the tire sidewall or, in the absence of such a marking, at a weight greater than that specified in any publication by an organization listed in the regulations, unless:

  • operated under the terms of a special state-issued permit
  • at a reduced speed not to exceed 50 miles per hour.

7. No motor vehicle shall be operated with any tire inflated less than the cold inflation pressure specified for the load.


It is worth determining whether the tires of any vehicle involved in a crash had sufficient tread or were somehow defective. Even if the proximate cause is not immediately obvious, it may appear later. In any event, bad tires on a CMV are extremely embarrassing to a motor carrier. The greater the number of such basic safety failures in a given case, the greater the chance someone with authority will decide to settle the matter.
Note that a driver can operate a CMV with an axle bearing on three tires instead of four, so long as the weight on the remaining tires does not violate this regulation:.

“Tire loading restrictions (except on manufactured homes). No motor vehicle (except manufactured homes, which are governed by paragraph (g) of this section) shall be operated with tires that carry a weight greater than that marked on the sidewall of the tire or, in the absence of such a marking, a weight greater than that specified for the tires in any of the publications of any of the organizations listed in Federal Motor Vehicle Safety Standard No. 119 unless:

(1) The vehicle is being operated under the terms of a special permit issued by the State; and
(2) The vehicle is being operated at a reduced speed to compensate for the tire loading in excess of the manufacturer’s rated capacity for the tire. In no case shall the speed exceed 80 km/hr (50 mph).”); A driver cannot operate a CMV with a flat tire. Again, however, just because the driver only has three tires on an axle does not automatically mean he is in violation. Some motor carriers may fill tires with a substance other than air. This may violate the Regulations, and should be investigated.

Some newer tractors feature systems that monitor the air pressure levels in tires. The readings of these systems may be recorded on the on-board computer of a CMV. This is worth analyzing, particularly if the cause of the crash is not apparent. It is possible that the tires were under-inflated for the type of load being carried.

Pertinent Case Law

Marcoux v. Farm Service and Supplies, Inc.

Using tires with shallow but visible tread was held not to constitute such outrageous conduct as to justify punitive damages under New York law in Marcoux v. Farm Service and Supplies, Inc. The Marcoux opinion is notable for its detailed description of what conduct will authorize the imposition of punitive damages in a trucking case, and cites to examples in numerous cases from New York and other jurisdictions.

Underwood v. Select Tire, Inc.

However, in Underwood v. Select Tire, Inc., the Georgia Court of Appeals reversed a grant of summary judgment for a tire manufacturer and installer where a regrooved truck tire mounted on a front axle blew out and caused a fatality crash. There, the court found that the Regulations prohibited the use of a regrooved tire on a front axle, which is not entirely correct, as the Regulations only prohibit tires with a certain load capacity from being used on a front axle. Assuming the court merely omitted this detail, the opinion is a significant one because the court found a duty existed on the part of the offending tire’s former owner to “appreciate[e] the importance of having the right tires for the right application.” The evidence showed that the former owner-seller was not a tire dealer, but rather a manufacturer of trailers who happened to have some used tires laying around, which the purchaser spotted while on the premises. The same rule was applied to the shop that mounted the tire.
Notably, Underwood involved at least eight expert witnesses that gave opinions on issues involving the truck’s tires and steering mechanism. The court found that a question of fact existed as to whether the tire installer had a duty to advise the buyer whether the tires in question were suitable for the intended installation and use (in this case, placement on the front axle of a tractor). Relying upon an analysis of the principles of ordinary negligence, the court also found a significant duty applicable to a casual seller of tires meant to be used in specialized applications.

Contact Information