Complying with federal tire regulations for commercial vehicles can reduce crashes and accident-related injuries and fatalities. Obeying the law can also reduce the risks of civil or criminal liability and save you time, effort and money. Government agencies have implemented standards to guide truck drivers and trucking companies in ensuring their tires are always in peak condition. While these requirements may seem complex, this article breaks them down to help you and your team understand your duties.
DOT Tire Regulations
The United States Federal Motor Carrier Safety Administration of the Department of Transportation and the Commercial Vehicle Safety Alliance set the standards for the manufacturing and use of commercial vehicle tires. Title 49 of the Code of Federal Regulations covers these in depth.
Title 49 CFR section 393.75 prohibits drivers from using tires with the belt material or body ply exposed through the sidewall or tread. Truck drivers must refrain from using:
- Tires with a sidewall or tread separation
- Tires that are flat or have audible leaks
- Tires with cuts that expose the ply or belt materials
The CVSA issues additional criteria annually, generally expanding on title 49 CFR section 393.75.
Trucking companies and truck drivers must comply with the regulations to reduce crashes and truck-related injuries and deaths. Also, doing so helps you avoid the FMCSA’s Compliance, Safety and Accountability violations — a scoring system established in 2010 to improve safety on our nation’s highways.
Under this system, tire violations can carry the heaviest penalties, adding up to eight points to your driving record. Eight-point tire violations include the following:
- Exposed ply, fabric or belt material
- Flat tire
- Audible air leaks
- Tread or sidewall separation
- Cuts exposing the ply or belt
- Poor tread depth
Three-point violations include the following:
- Underinflated tires
- Regrooved tires
- Tire load weight rating
Why Should You Comply With the FMCSA Tire Regulations?
Here are five reasons you must comply with the FMCSA tire regulations.
- Increase safety: The DOT keeps road users safe through initiatives like CSA scoring and DOT tire regulations. The rules serve as preventive measures that can control unexpected blowouts. For example, using the recommended tires and ensuring regular checks can help you identify defects quickly.
- Avoid sanctions: The DOT tire regulations are federal laws commercial drivers must comply with. The FMCSA can put your truck out of service if you fail to follow the laws.
- Avoid civil and criminal liability: Complying with FMCSA tire regulations decreases the chances of reckless or negligent driving and accidents, saving you from costly lawsuits, criminal prosecutions and potential jail time.
- Performance and fuel efficiency: Properly inflated and well-balanced tires with good tread can reduce rolling resistance, helping you save fuel, since the vehicle requires less force to move. Responsible tire usage also improves the vehicle’s performance.
- Vehicle longevity: Repairing and replacing commercial vehicles can be expensive, making it advisable to comply with DOT regulations. Reducing accidents keeps your truck safe and ready for business. You can save the money you’d otherwise spend on replacements or repairs to increase your fleet size.
What Are DOT Regulations for Tire Manufacturers and Drivers?
Here are the tire regulations and standards for commercial truck drivers.
1. DOT Tire Tread Depth
Tread depth is a vertical measurement on the tire, from the top of the rubber to the bottom of the groove. It affects the vehicle’s acceleration, braking and fuel economy. U.S. drivers measure their tread depth in fractions of an inch. Countries that use the metric system measure in millimeters.
According to DOT tire regulations, the minimum tire tread depth for steer tires or any tire on the front wheel is 4/32 of an inch. The other tires must have a minimum tread depth of 2/32 of an inch. The CVSA also has minimum tread depth, which is less stringent than the DOT’s. The CVSA requires steer tires to have a minimum tread depth of 2/32 of an inch, while every other tire must have a minimum depth of 1/32 of an inch.
2. DOT Tire Pressure Regulations
Correctly inflated tires improve the vehicle’s performance. They allow the truck to move efficiently, especially when carrying a load across destinations. As such, the DOT prohibits truck drivers from using vehicles with tires that have cold inflation pressure below the specified requirement. The required pressure depends on the load the truck is carrying.
If heat causes the tire’s pressure to increase due to recent operations, you can estimate the cold inflation pressure by deducting the inflation buildup factor from the measured inflation pressure. Heat can cause tire air pressure to increase, leading to inaccurate readings and driving with underinflated tires. Driving with flat tires can drive up your CSA score, which you must avoid if you want to keep using the vehicle.
The law allows drivers to remove the defective tire from the axle and drive with three tires on an axle instead of four if the remaining tires are within the maximum weight limit.
3. DOT Steer Tire Regulations
The DOT steer tire regulations are standards commercial vehicle drivers and trucking companies must follow to ensure the front or steer tires are in good condition. As discussed earlier, one aspect of the rule relates to minimum legal tread depth, which provides sufficient traction on the road in wet or slippery conditions. Another part of the regulation refers to the steer tire condition.
The front tires must be free from cuts, bulges, cracks and other physical damages capable of causing blowouts. The tires cannot have exposed belts or cords, and the weight must be within the amount stated on the sidewall.
FMCSA steer tire regulations also prohibit truck drivers from using retreaded or regrooved tires in the front tires. This rule applies to buses, truck tractors and large trucks.
4. DOT Tire Age Laws
Tires experience wear and tear like every other truck component, so you should expect the rubber to break down over time. While no specific DOT tire age laws exist, routine inspections and replacements are an industry best practice. Tire life span depends on factors like tire quality, maintenance, usage pattern and environmental conditions. Also, tires can age when not in use, so checking your spare is vital.
Even when tires appear to have a lot of remaining tread, they may have compromised integrity. Though the defects can sometimes be challenging to detect, ensuring proper pressure maintenance, tread monitoring and regular inspection is crucial.
Learn More From Hazmat School
Hazmat School offers competitively priced online and in-person DOT courses aimed at improving knowledge and helping truckers and trucking companies comply with the laws. Our flexible and practical programs have professional instructors available 24/7 to address your concerns. Visit our course page now or contact us to learn more!