What is a signal that a vehicle is about to change lanes?

The use of the turn signal indicator is a standard and universally recognized method for indicating a vehicle's intention to change lanes. When a driver activates the turn signal, it provides a visual warning to other road users that the vehicle is about to make a lateral movement, such as merging into another lane. This helps create a safer driving environment by allowing other drivers to anticipate the action and adjust their driving accordingly.

The turn signal serves an essential function in communication on the road. It informs surrounding drivers, bicyclists, and pedestrians of the driver's intentions, reducing the risk of collisions and promoting smoother traffic flow. Proper use of turn signals is not only a safe practice but also a legal requirement in most regions.

In contrast, flashes of headlights, steering wheel movement, or brake lights may not clearly convey the intent to change lanes. Headlight flashes can sometimes be interpreted in different ways, steering wheel movements may not be observable until the lane change begins, and brake lights indicate a decrease in speed rather than a change of direction. Therefore, the turn signal indicator is the most effective and recognized signal for signaling a lane change.