What do tread wear indicators on tires signify?

Tread wear indicators are vital safety features located in the grooves of a tire that help assess the tread depth. When the tread wears down to a certain level, these indicators become more visible, typically sitting flush with the tread surface. This visibility signifies that the tire has reached a point where it is no longer safe for driving, as insufficient tread can reduce traction, especially in wet conditions, increasing the risk of hydroplaning and accidents.

While tire rotation, alignment issues, and air pressure are important aspects of tire maintenance, they are not directly indicated by the wear indicators. Instead, those factors might manifest through other physical signs or changes in vehicle handling, but the wear indicators specifically signal that the tread has worn down to a level that necessitates tire replacement for safety reasons.