Evaluating Drivers’ Understanding of Warning Symbols Presented on In-Vehicle Digital Displays Using a Driving Simulator

Abstract

<div class="section abstract"><div class="htmlview paragraph">Since 1989, ISO has published procedures for developing and testing public information symbols (ISO 9186), while the SAE standard for in-vehicle icon comprehension testing (SAE J2830) was first published in 2008. Neither testing method was designed to evaluate the comprehension of symbols in modern vehicles that offer digital instrument cluster interfaces that afford new levels of flexibility to further improve drivers’ understanding of symbols.</div><div class="htmlview paragraph">Using a driving simulator equipped with an eye tracker, this study investigated drivers’ understanding of six automotive symbols presented on in-vehicle displays. Participants included 24 teens, 24 adults, and 24 senior drivers. Symbols were presented in a symbol-only, symbol + short text descriptions, and symbol + long text description conditions. Participants’ symbol comprehension, driving performance, reaction times, and eye glance times were measured.</div><div class="htmlview paragraph">The results of this study suggested that presenting automotive symbols on in-vehicle displays with text descriptions significantly improved drivers’ understanding of the symbols. Eye glance off the road times, symbol reaction times, and the self-reported cognitive workload measures suggested that text descriptions may increase distraction but did not effectively degrade driving performance.</div><div class="htmlview paragraph">Overall, this study demonstrates that the current SAE and ISO symbol’s comprehension testing, and the comparison of alternative methods to communicate information on in-vehicle displays may benefit from additional tests in a dynamic setting, such as those offered by a driving simulator.</div></div>