Optically-Controlled Braking Responses to Variable Deceleration Magnitudes in a Car-Following Task

This study sought to identify which braking strategies are more often used in a car-following task when only optical cues to deceleration are available (no brake lights). Previous research identified three braking strategies for stopping to a stationary obstruction: regulation (deceleration at a near-constant magnitude), slam-on-the-brakes (increasing magnitude of deceleration), and bang-bang (initial high deceleration followed by a less deceleration). We used a car-following task with braking profiles which included variable decelerations to examine which of these strategies is most often used when drivers are not presented with brake lights warning of the deceleration of the lead vehicle. Results showed that individuals tend to use the slam-on-the-brakes approach (soft-then-hard braking) more than regulated (constant braking) or a bang-bang approach (hard-then-soft braking) when following vehicles without brake lights. These data form an important baseline of behavior for evaluating the effects of brake lights and other deceleration displays on braking behavior.