You check the tire tread by taking a measurement in the center of the tread with a tire tread depth indicator in 3 places 1/3 the way around the tire and that will indicate the wear on the tire.
How To Measure Tire Tread >> How to measure tire tread and use a tire depth gauge - YouTube

How To Measure Tire Tread >> How to measure tire tread and use a tire depth gauge - YouTube

The amount of tread on a tire is critical in determining how well it will vacate water to maintain contact with the road in the rain. If your tires wear out quickly, your safety may be at risk.
How To Measure Tire Tread >> Tire Tread Depth Chart | World of Reference

How To Measure Tire Tread >> Tire Tread Depth Chart | World of Reference