What might be indicated by a visible wear indicator on brake pads?

A visible wear indicator on brake pads serves as a direct visual cue about the condition of the brake pads. When the wear indicator shows signs of wear, it typically means that the brake pads have reached a level where they require immediate attention and likely need to be replaced. This feature is designed to alert the driver that the brake pads are becoming too thin and, therefore, may not perform effectively in stopping the vehicle.

In some designs, a wear indicator may create a squeaking noise to indicate that the pads are excessively worn, hence reinforcing the need for replacement. Optimal brake pad condition would not display a wear indicator, and any need for lubricating or cleaning does not pertain to the function of the wear indicator; rather, those actions are preventative maintenance tasks unrelated to the visual cue of brake pad wear.