Supplementary data for the paper: Cross-national differences in drivers’ eye contact and traffic violations: An online survey across 20 countries

The advent of self-driving cars has sparked discussions about eye contact in traffic, particularly due to challenges that automated vehicles face in non-verbal communication with human road users. In his 1992 book, <em>Turn Signals Are The Facial Expressions Of Automobiles</em>, Don Norman describes how drivers in Mexico City deliberately avoid eye contact when entering a roundabout to create uncertainty in the minds of other drivers, leading the latter to yield right of way. Norman argued that such manipulative or aggressive behavior would not be tolerated in the United States. In the present study, we tested these claims through an online survey involving 3,857 respondents from 20 countries. The results confirmed that Mexican drivers reported a higher frequency of non-speeding ‘aggressive’ violations compared to those from most other countries. Regarding eye contact in roundabout scenarios, national differences were found not so much in the frequency of eye contact but in the reasons behind its use. Mexican drivers tended to avoid eye contact to reduce tension or avoid conflict with other drivers. However, they also frequently reported making eye contact to assert or subtly enforce their right of way. In higher-income countries like the United States, driver-driver eye contact is often deemed unnecessary. In conclusion, our findings partially correspond with Norman’s anecdote based on his experiences in 1950 s Mexico City. These results may have implications for understanding the stability of traffic cultures and the challenges related to eye contact and non-verbal communication faced by developers of automated vehicles.

自动驾驶汽车的问世引发了学界对交通场景中眼神交流的探讨，尤其是由于自动驾驶车辆在与人类道路使用者开展非语言沟通时面临诸多现实挑战。1992年，唐·诺曼（Don Norman）在其著作《转向灯即为汽车的面部表情》中描述道，墨西哥城的驾驶员在驶入环岛时会刻意规避眼神交流，借此在其他驾驶员心中制造不确定性，进而促使对方礼让先行权。诺曼提出，此类带有操纵性或攻击性的驾驶行为在美国是无法被容忍的。本研究通过一项覆盖20个国家、共3857名受访者的线上调查，对上述论断进行了实证检验。研究结果证实，相较于绝大多数其他国家的驾驶员，墨西哥籍驾驶员报告的非超速“攻击性”交通违规行为发生频率显著更高。针对环岛场景下的眼神交流，各国之间的差异更多体现在使用眼神交流的动机层面，而非其发生频次。墨西哥驾驶员往往会通过避免眼神交流来缓解紧张情绪或规避与其他驾驶员的冲突，但他们也常会借助眼神交流来主张或隐性行使自身的先行权。在美国等高收入国家，驾驶员之间的眼神交流通常被视为无必要之举。综上，本研究结果部分印证了诺曼基于其1950年代墨西哥城经历所提出的轶事性论断。上述发现可为理解交通文化的稳定性，以及自动驾驶车辆开发者在眼神交流与非语言沟通领域面临的相关挑战提供参考。