Evaluating the Impact of Warning Modalities and False Alarms in Pedestrian Crossing Alert System

TL;DR

This study compares how different alert modalities in pedestrian crossing systems affect driver response and trust, highlighting the benefits of multimodal alerts and the negative impact of false alarms.

Contribution

It provides new insights into the effectiveness of audio-visual, tactile, and combined alert modalities in improving pedestrian safety in driving simulators.

Findings

Multimodal alerts increase vehicle stopping and safety distance.

False alarms reduce driver trust and cause caution and fatigue.

Some drivers fully stopped despite no pedestrian presence.

Abstract

With the steadily increasing pedestrian fatalities, pedestrian safety is a growing concern, especially in urban environments. Advanced Driver Assistance Systems (ADAS) have been developed to mitigate road user risks by predicting potential pedestrian crossings and issuing timely driver alerts. However, there is limited understanding of how drivers respond to different modalities of alerts, particularly in the presence of false alarms. In this study, we utilized a full-scale driving simulator to compare the effectiveness of different alert modalities, audio-visual (AV), visual-tactile (VT), and audio-visual-tactile (AVT), in alerting drivers to various pedestrian jaywalking events. Our findings reveal that, compared to no alerts, multimodal alerts significantly increased the number of vehicles stopped for pedestrians and the distance to pedestrians when stopped. However, the false alarms negatively impacted driver trust, with some drivers exhibiting excessive caution, alert fatigue and anxiety, even including one instance where a driver fully stopped when no pedestrian was present.