What might indicate a lane change violation?

Not signaling while changing lanes is a clear indication of a lane change violation because signaling is a fundamental aspect of safe driving practices. Proper use of turn signals ensures that other road users are aware of a driver's intentions to change lanes. When a driver fails to signal, it can lead to confusion and unexpected movements from other vehicles, increasing the risk of collisions. This lack of communication is considered a violation in many jurisdictions because it goes against the rules designed to promote safety and predictability on the road.

The other choices reflect safe driving practices rather than violations. Maintaining the speed limit while changing lanes is in accordance with traffic laws and does not constitute a violation. Checking mirrors before a lane change is a safety measure that reflects responsible driving behavior. Similarly, using turn signals correctly is the right action to take when changing lanes, as it helps prevent misunderstandings among drivers.