What indicates that a tire must be removed from service?

The indication that a tire must be removed from service includes visible bulges on the tire. Bulges can indicate internal damage or separation of the tire structure, which compromises its integrity and can lead to blowouts or loss of control while driving. Therefore, if you spot bulges, it is a clear sign the tire is unsafe for use and should be replaced immediately.

While the condition noted in your answer regarding tread depth and wear is important for assessing overall tire health, visible bulges are a more immediate indication of a potentially dangerous situation. Tread wear indicators may suggest a tire is getting close to the end of its usable life but do not represent an acute failure that can occur with bulging. Therefore, checking for bulges helps tire professionals ensure safety and performance on the road.