Under which circumstance does a driver's license become invalid?

A driver's license becomes invalid when it is too worn out to determine ownership because the ability to clearly identify the license holder is crucial for both legal and safety reasons. If critical information such as the name, photo, or signature is not legible, law enforcement and other authorities cannot confirm the identity of the driver. This creates a situation where the license no longer serves its purpose as a valid form of identification.

Other circumstances presented do not inherently render a license invalid. For instance, a misplaced license can be replaced through proper channels, thus maintaining its validity upon replacement. Similarly, turning 50 years old does not affect the legality of the license itself, as age alone is not a disqualifying factor. Lastly, a driver's license remains valid regardless of any accidents involving the vehicle, provided the license holder has not committed any violations that would lead to its suspension or revocation.