Situational Awareness, Drivers Trust in Automated Driving Systems and Secondary Task Performance
URL: http://arxiv.org/abs/1903.05251v1
archive: archived pipeline: cataloged verified
Abstract
Driver assistance systems, also called automated driving systems, allow drivers to immerse themselves in non-driving-related tasks. Unfortunately, drivers may not trust the automated driving system, which prevents either handing over the driving task or fully focusing on the secondary task. We assert that enhancing situational awareness can increase trust in automation. Situational awareness should increase trust and lead to better secondary task performance. This study manipulated situational awareness by providing them with different types of information: the control condition provided no information to the driver, the low condition provided a status update, while the high condition provided a status update and a suggested course of action. Data collected included measures of trust, trusting behavior, and task performance through surveys, eye-tracking, and heart rate data. Results show that situational awareness both promoted and moderated the impact of trust in the automated vehicle, leading to better secondary task performance. This result was evident in measures of self-reported trust and trusting behavior.
Summary
Within-subjects driving-simulator study (N=30 analyzed of 33 recruited; 22 male, 8 female; mean age 25.7 yrs) testing how three levels of auditory situational-awareness support (control / low: 'stopped vehicle ahead' / high: status update plus 'no action needed' or 'take control now') affect trust in a semi-automated vehicle and surrogate-reference-task (SuRT) performance. Each participant completed three ~10-min sessions (Latin-square counterbalanced) encountering four stopped vehicles per session on a simulated 2-lane 70-mph highway, with eye-tracking, heart-rate, and post-session SART and Muir/Moray trust surveys. Mixed linear models (SPSS v24) tested condition effects.
Key finding
High-SA audio (status + recommended action) raised composite SART scores and self-reported trust over control, reduced on-road monitoring ratio (0.125 vs 0.180), and let drivers wait longer (9,900 ms vs 8,000 ms in low-SA) and stay in-lane closer (85 m vs 130 m in low-SA) before taking control. The moderation model indicated SA both promoted and amplified the effect of trust on secondary-task performance.
Methodology
One-way within-subjects driving-simulator experiment; static three-screen ANVEL simulator with HUD; surrogate reference task on a 10.1-inch right-side touchscreen (PEBL); head-mounted eye-tracker; heart-rate monitor (BPM and rMSSD HRV); post-condition SART (DAR, SAR, UOS) and Muir & Moray (1996) trust surveys; Latin-square ordering; mixed linear models with moderation.
Sample size: 30 (33 recruited, 3 excluded for simulation errors); 22 male, 8 female; mean age 25.7 (SD 5.5)
Quality score: 5 / 5