Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea.
Accid Anal Prev. 2021 Mar;151:105909. doi: 10.1016/j.aap.2020.105909. Epub 2020 Dec 25.
Ground-level traffic lights or safety signs have been introduced recently as a prevention measure for smartphone-related pedestrian accidents. However, quantitative evaluation of smartphone users' detection performance during distracted walking has been scarce. A laboratory experiment was conducted to evaluate the performance of detecting ground-level visual cues during the concurrent use of a smartphone while walking. Thirty-eight young smartphone users performed ground-level visual cue detection trials, 1) while walking upright on a treadmill without using a smartphone; 2) when conducting one-handed browsing while walking; and, 3) when conducting two-handed texting while walking. Visual cues were presented on the ground at 24 locations by a ceiling-mounted projector, and participants were asked to respond verbally when they perceived the appearance of each cue. Study results show that the concurrent use of a smartphone decreased the detection rate significantly (p < 0.05) from 93.5 % to 76.3∼74.1 %, and increased the reaction time from 0.90 s to 1.04∼1.15 s. Among the 24 cue locations, cues that were presented closer to participants were detected significantly (p < 0.05) more often and faster than cues that were shown at further locations. The results of this laboratory-based study imply that the ground-level signals might not be detected well by smartphone users, specifically when they were conducting more demanding tasks such as texting while walking. However, the laboratory conditions were confined to a specific usage environment; therefore, future research should be focused on the situation awareness of smartphone users under various usage scenarios and more realistic environments.
最近引入了地面交通信号灯或安全标志作为预防智能手机相关行人事故的措施。然而，对于智能手机用户在分心行走时检测地面视觉线索的性能，定量评估还很少。进行了一项实验室实验，以评估在同时使用智能手机行走时检测地面视觉线索的性能。38 名年轻的智能手机用户进行了地面视觉线索检测试验，1）在没有使用智能手机的跑步机上直立行走；2）在行走时进行单手浏览；3）在行走时进行双手发短信。视觉线索由天花板安装的投影仪在地面上的 24 个位置呈现，参与者被要求在感知到每个线索出现时口头做出反应。研究结果表明，智能手机的同时使用显著降低了检测率（p<0.05），从 93.5%降至 76.3∼74.1%，反应时间从 0.90 秒增加到 1.04∼1.15 秒。在 24 个线索位置中，靠近参与者呈现的线索被检测到的频率和速度明显更高（p<0.05），而距离更远的线索则较慢。这项基于实验室的研究结果表明，地面信号可能无法被智能手机用户很好地检测到，特别是当他们进行更具挑战性的任务，如行走时发短信。然而，实验室条件仅限于特定的使用环境；因此，未来的研究应该侧重于各种使用场景和更现实环境下智能手机用户的情境意识。
