College of Traffic and Transportation, Chongqing Jiaotong University, Chongqing 400074, China.
Chongqing Chang'an Automobile Co., Ltd., Chongqing 400023, China.
Int J Environ Res Public Health. 2022 Nov 17;19(22):15191. doi: 10.3390/ijerph192215191.
Distractors faced by drivers grow continuously, and concentration on driving becomes increasingly difficult, which has detrimental influences on road traffic safety. The present study aims to investigate changes in driving workload and driving performance caused by distracting tasks. The recruited subjects were requested to drive along a city route in a real vehicle and perform three secondary tasks sequentially. Electrocardiography and driving performance were measured. Heart rate variability (HRV) was adopted to quantitatively analyze the driving workload. Findings show that: (i) increments are noticed in the root mean square differences of successive heartbeat intervals (RMSSD), the standard deviation of normal-to-normal peak (SDNN), the heart rate growth rate (HRGR), and the ratio of low-frequency to high-frequency powers (LF/HF) compared to undistracted driving; (ii) the hands-free phone conversation task has the most negative impacts on driving workload; (iii) vehicle speed reduces due to secondary tasks while changes in longitudinal acceleration exhibit inconsistency; (iv) the experienced drivers markedly decelerate during hands-free phone conversation, and HRGR shows significant differences in both driving experience and gender under distracted driving conditions; (v) correlations exist between HRV and driving performance, and LF/HF correlates positively with SDNN/RMSSD in the hands-free phone conversation and chatting conditions while driving.
驾驶员面临的干扰因素不断增加，集中精力驾驶变得越来越困难，这对道路交通安全有不利影响。本研究旨在调查分心任务引起的驾驶工作量和驾驶性能的变化。招募的受试者被要求在真实车辆中沿着城市路线行驶，并依次执行三个次要任务。测量了心电图和驾驶性能。心率变异性（HRV）用于定量分析驾驶工作量。结果表明：（i）与不分散注意力的驾驶相比，连续心跳间隔的均方根差（RMSSD）、正常到正常峰值的标准差（SDNN）、心率增长率（HRGR）和低频与高频功率比（LF/HF）都有所增加；（ii）免提电话交谈任务对驾驶工作量的负面影响最大；（iii）由于次要任务，车速降低，而纵向加速度的变化不一致；（iv）有经验的驾驶员在免提电话交谈时明显减速，在分心驾驶条件下，HRGR 在驾驶经验和性别方面都有显著差异；（v）HRV 与驾驶性能之间存在相关性，在免提电话交谈和聊天条件下，LF/HF 与 SDNN/RMSSD 呈正相关。
