When is a signal turn indicator required on a motor vehicle?

A signal turn indicator is required on a motor vehicle when the vehicle is changing lanes. This is a critical safety measure designed to inform other drivers of the vehicle's intended maneuvers, thus helping to prevent accidents. Using turn signals during lane changes is not just a good practice; it is mandated by traffic laws in many jurisdictions, including Texas.

The requirement to signal while changing lanes emphasizes the importance of communication on the road, allowing for smoother traffic flow and greater awareness among drivers. This rule applies regardless of whether the turn is to the left or right, ensuring that all drivers are operating with transparency about their actions, which is vital in maintaining road safety.

While signaling can also be required in specific situations like parking or making perpendicular turns, the most fundamental and common requirement relates to lane changes, where the risk of collision is higher without appropriate signaling.