Traffic crashes with small-displacement motorcycles constitute a major health concern in motorcycle-dominant countries such as Vietnam. The purpose of this study was to improve our understanding of typical characteristics of small-displacement motorcycle crashes in Vietnam, mainly focusing on the prevalence and role of risky riding behaviours, the dangers associated with risky ridership, and the underlying motives. To that purpose, a qualitative study design was implemented, including a series of focus group discussions and in-depth interviews based on a semi-structured format with different stakeholders involved in motorcyclist safety. In terms of perceived risk, drink-riding, speeding, and inattentive riding were evaluated as the three most dangerous behaviours. The occurrence of riding under the influence of alcohol was attributed to four main underlying motives, i.e., alcohol-induced ‘false’ sense of safety, several contextual barriers preventing the adoption of safe alternatives to riding back home after having drunk, the financial cost associated with using alternative transport to return safely after drinking, and perceived unsafety of motorcycle taxi services. As for speeding, four main sub-themes emerged from the discussions as underlying motives, i.e., ‘being in a hurry’, ‘showing off’, ‘competitiveness’, and ‘thrill seeking’. Finally, inattentiveness was associated with the four following underlying motives: ‘use of mobile device’, ‘attention/search conspicuity’, ‘mind-wandering’, and ‘interaction with pillion passenger’. Overall, this suggests that risky rider behaviours are best explained as a dual process phenomenon where risk-related decisions can be under volitional control and/or guided by a reactive pathway where people demonstrate an unintentional willingness to expose themselves to danger under specific risk-conducive circumstances. Crash-prone environmental conditions for Vietnamese small-displacement motorcyclists mentioned, were heavy rain, high temperature, strong wind, dust, potholes, and other forms of pavement deterioration, as well as geometric alignment reducing intersection visibility. These findings are further translated into practical recommendations for academic researchers, policymakers, and practitioners.

在越南等以摩托车为主的国家，小排量摩托车的交通事故构成了主要的健康问题。本研究的目的是提高我们对越南小排量摩托车事故典型特征的理解，主要关注危险骑行行为的普遍性和作用、与危险骑行相关的危险以及潜在动机。为此，实施了定性研究设计，包括一系列焦点小组讨论和基于半结构化格式的深入访谈，涉及摩托车手安全的不同利益相关者。在感知风险方面，酒驾、超速和不专心骑行被评估为三种最危险的行为。在酒精影响下骑车的发生归因于四个主要的潜在动机，即酒精引起的“错误”安全感，一些背景障碍阻止采用酒后骑车的安全替代方案，相关的财务成本酒后使用替代交通工具安全返回，并认为摩托车出租车服务不安全。至于超速，讨论中出现了四个作为潜在动机的主要子主题，即“赶时间”、“炫耀”、“竞争力”和“寻求刺激”。最后，注意力不集中与以下四个潜在动机有关：“使用移动设备”、“注意/搜索显眼”、“走神”和“与后座乘客互动”。总体，这表明，危险的骑手行为最好解释为双重过程现象，其中与风险相关的决策可以在意志控制下和/或由反应路径引导，在这种情况下，人们表现出在特定的有利于风险的情况下无意中暴露自己的危险。提到的越南小排量摩托车容易撞车的环境条件是大雨、高温、强风、灰尘、坑洼和其他形式的路面恶化，以及几何对齐降低了交叉路口的能见度。这些发现进一步转化为对学术研究人员、政策制定者和从业者的实用建议。