Tire tread depth

Maintenance/Repairs
1

I drive a commercial vehicle on a class “c” license in North Carolina. The tread on some of these vehicles is really bad, but the mechanics say that they are within specs. What is the minimum tread depth on these vehicles and how is it measured? Are the tires considered bald if any one point on the tires measures too thin?

2

This is a question that may concern both state and federal regulations, so you need to read the regulations to determine which are applicable.

Here’s what Kevin Rohlwing of the Tire Industry Association had to say about it:

But you will find many publications that say that for snow traction 5/32nds is the minimum, for wet conditions: 4/32nds and for dry: 2/32nds.

But this is a recommendation, not a legal requirement.

You might consider stopping at one of those weigh stations and asking. But DO NOT stop if you think the tires on YOUR truck might fall below the minimum. You could wind up having your truck impounded until the tires have been replaced - and that probably would jeopardize your employment.

3

Federal standards for commercial trucks are the following: the steering tires must have at least 4/32 of an inch of tread. All other tires must have at least 2/32 of an inch of tread. This standard applies to the part of the tire with the least amount of tread, so check in more than one place on each tire.

The only way to know for sure is to use a tire tread depth gauge. As a professional driver, your vehicle must pass your pre-trip inspection before you drive it. If you deem a vehicle unsafe, there are federal “whistle blower” laws that will protect you for refusing to drive such a vehicle.

Because professional drivers are expected to conduct pre-trip inspections before they get behind the wheel, if something happens and someone dies, it is likely you would be held liable, even if you brought this concern to your employer. As the driver, you are expected to ensure the vehicle is safe. This includes things other than tires, within reason. You are expected to check everything that can be inspected visually.