For what reason might the DMV require additional testing during renewal of a Class C license?

The DMV may require additional testing during the renewal of a Class C license if there is a concern about the driver's ability. This could relate to a variety of factors that might indicate a decline in driving skills or an increased risk to public safety. Examples might include a history of accidents, traffic violations, medical conditions that could impair driving, or concerns raised by law enforcement or medical professionals. The intent behind this requirement is to ensure that all drivers on the road are capable of operating a vehicle safely and responsibly.

Factors such as age, previous test performance, or individual requests can influence the situation, but they do not inherently warrant mandatory additional testing unless there is a direct concern regarding the driver's competence to operate a vehicle safely.