Informing drivers via wearable devices: Impacts of tactile warning locations on takeover performance in automated driving

Fangda Zhang ¹, Lin Jie ², Le Zou ²

⁰The Center for Injury Research and Policy, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.

Ergonomics +

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December 26, 2025

View abstract on PubMed

Summary

This study explored tactile takeover requests (TORs) in automated driving using wearable devices. Ear warnings improved reaction times, while wrist warnings offered better user acceptance, suggesting placement impacts safety and preference.

Area Of Science

Human-Computer Interaction
Automotive Ergonomics
Wearable Technology

Background

Driver takeover performance is crucial for Level 3 automated driving safety.
Designing effective takeover requests (TORs) is a key research area.
Tactile TORs via wearable devices offer a novel approach to driver alerts.

Purpose Of The Study

To investigate the impact of tactile warning location on driver takeover performance and user acceptance.
To compare the effectiveness of ear, wrist, abdomen, and tibia tactile cues during non-driving-related tasks (NDRTs).

Main Methods

A driving simulator experiment was conducted with 36 participants.
Tactile TORs were delivered through wearable devices at four distinct body locations.
Takeover performance metrics and user acceptance were evaluated under varying NDRT conditions.

Main Results

Ear-based tactile warnings resulted in the fastest driver reaction times.
Tibia-based warnings led to the strongest braking responses.
Wrist-based warnings achieved the highest user acceptance ratings, despite slightly longer reaction times.

Conclusions

Tactile warning placement significantly influences both objective takeover performance and subjective user preference.
A trade-off exists between maximizing performance and ensuring user acceptance.
Ear-based cues are recommended for urgent takeovers, while wrist-based cues are suitable for routine scenarios, informing user-centered haptic interface design in automated vehicles.

Keywords:

NDRT Tactile warnings level 3 driving automation takeover performance wearable devices