What is one of the most critical reasons for using turn signals?

Using turn signals is essential primarily because they inform other drivers of a vehicle's intended movements, which significantly enhances safety on the road. When a driver uses their turn signal, it communicates to others around them that they plan to change lanes, turn, or make a maneuver. This allows other drivers to anticipate the movement, reducing the likelihood of accidents caused by sudden or unexpected actions.

The use of turn signals is a fundamental part of defensive driving, as it promotes clear communication between drivers. When everyone follows this practice, it contributes to a smoother flow of traffic and helps maintain order on the roads. Moreover, it allows pedestrians and cyclists to understand a driver's intentions, contributing to their safety as well.

While indicating speed, alerting pedestrians, and complying with registration laws are significant aspects of road safety and legality, they do not pertain directly to the primary function of turn signals, which is to communicate intended movements to improve safety for all road users.