Tire Size, Thread Depth, Width and Snow Chains Regulations (USA and Canada)
Tire Size and Type
Ensure that your vehicle is equipped with the proper tire size and type. Reference your owner’s manual for the manufacturer’s specifications.
The air pressure of a vehicle’s tire should always be checked when the tires are cold. Driving even a short distance causes tires to become warm, which increases the air pressure and can give you an inaccurate air pressure reading. Under inflated tires can overheat and endanger lives. A tire can lose up to half of its air pressure and not appear to be flat. Refer to your vehicle’s owner manual for the recommended tire pressure. The tire sidewall displays the MAXIMUM allowable pressure for that specific tire, NOT the proper inflation. Check tires monthly with a tire gauge to ensure proper air pressure and safety.
Tread grooves are designed to push water out from under the tread allowing the tire to make maximum contact with the road. If tires are worn, they are more likely to hydroplane. There are specified legal tread depths for tires. Tires have built-in treadwear indicators, which are raised sections that run in between the tire’s tread. When the tread is worn down so that it’s level with the tread indicator, it’s time to replace your tires. Another good rule of thumb is to do the penny test. Insert a penny into a tread groove with the top of Lincoln’s head facing down. If you can see above the top of his head, your tires have less than 2/32” of tread should be replaced immediately.
Tire Rotation and Alignment
Tires should be rotated every 5,000 miles or as required by the manufacturer. This ensures that your tires will wear evenly, prolonging the life of the tire and ensuring motorist safety. Follow the tire rotation pattern provided in the vehicle’s owner manual.
An unusual vibration or thumping noise may indicate and out-of-balance tire. Have your tire alignment checked promptly if you experience these symptoms or issues with maneuverability.
(1) Each axle on a Turnpike Tandem must have tires of the same size and construction. Tires must be properly inflated for the load to be carried. In no event shall any tire, wheel, or rim exceed the manufacturer’s maximum load-carrying limit. Tires and tire usage must be consistent with the requirements of 49 C.F.R., 393.75, as required by Section 316.302(1), F.S.
(2) A vehicle equipped with dual tires may have the dual tires replaced by a single tire so long as the vehicle, axle, and tire load ratings are not exceeded.
(3) No tire may exceed 550 pounds per inch of tire section width as defined by the rating molded in the tire sidewall. For example, a designation of 445/50R22.5 designates a tire section width of 445 mm (17.5 inches).
Below is a list of states and their tire regulations.
Click on the states below for links to the state's guidelines for for tire regulations for commercial vehicles / heavy haul shipping. These regulations are subject to change for each state. If something doesn't look correct, give us a shout and let us know so we can property update the page.