TURN SIGNAL USE AS AN ELEMENT OF ACTIVE TRAFFIC SAFETY

Turn signals are one of the basic elements of communication between road users and play a significant role in a vehicle's active safety system. Through their timely and proper use, the driver unequivocally signals their intention to other road users to change direction, change lanes, turn, or enter and leave the traffic stream. In addition to not using turn signals, a significant safety problem also arises when a turn signal remains on after the maneuver is complete. Such signaling can provide other road users with incorrect information about the vehicle's intended movement and influence their decisions, especially at intersections, when merging onto a road with right-of-way, changing lanes, and in other complex traffic situations. The automatic cancellation of the turn signal in most passenger vehicles is linked to the steering wheel's rotation and return motion, which is why it may not automatically cancel during certain maneuvers and at smaller steering angles. The paper analyzes the use of turn signals from an active safety perspective, with particular emphasis on the relationship between automatic turn signal cancellation and steering wheel angle. The results of the authors' previous research showed that in vehicles with a conventional mechanical system, the turn signal automatically cancels after a sufficient steering angle has been reached, when the steering wheel returns to a position of approximately 20–30° relative to the zero position, while a steering wheel angle of approximately 45° is required to activate the mechanism. An analysis of characteristic maneuvers considered situations in which the turn signal may remain active after the maneuver is completed, with a special focus on changing lanes and exiting a roundabout. The analysis results indicate that a turn signal that remains active after the maneuver can provide other road users with incorrect information about the vehicle's future path, thereby contributing to misjudgment of the traffic situation and the occurrence of conflicts.