Impact of countdown timer on drivers’ anticipation at the onset of yellow at signalized intersections

ABSTRACT

Countdown timers at traffic signals display the time remaining for a phase to terminate, influencing driver behaviour. Studies on their effects at the onset of yellow have generally focused on drivers’ stop/go decisions and dilemma zone, without explicitly addressing how they help drivers anticipate the signal change and make ‘informed decisions’. Therefore, this study first analysed the impact of countdown timer on drivers’ anticipation by comparing brake initiation, deceleration, and speed in the absence and presence of countdown timer. Next, driver behaviour was studied using ‘Accelerated Failure Time’ models. A driving simulator experiment was designed for data collection, with demographic and additional driving behaviour data gathered through a questionnaire. When countdown timer was present, drivers anticipated the onset of yellow, resulting in significant variations in driver behaviour. These variations, in turn, influenced the duration of braking and the time taken to cross the stop line from the onset of yellow.

KEYWORDS:

• Countdown timer
• anticipation
• brake initiation
• informed decision-making
• accelerated failure time

Acknowledgments

The authors would like to thank Dr. Bharat Pathivada, former Research Scholar at IIT Bombay and Dr. P. Vedagiri, Professor at IIT Bombay, for sharing the traffic video data for study validation.

Disclosure statement

No potential conflict of interest was reported by the author(s).