Reducing risky behaviors and traffic violations is crucial for preventing road trauma among private and commercial motorcyclists. While legal interventions such as road rules and police enforcement have been somewhat effective, there is a gap in understanding how motorcyclists perceive these deterrents and the psycho-social factors influencing their effectiveness. This research aims to explore the interplay between motorcyclists’ psycho-social predispositions and their responses to legal interventions. It also compares two distinct groups of riders - private and commercial motorcyclists - within the urban environment of Da Nang, Vietnam, providing a nuanced consideration of the influence of work-related impacts on risky behavior, which can enable targeted interventions. We propose a theoretical model integrating the Theory of Planned Behavior and Deterrence Theory to analyze how psycho-social and punitive factors influence riders’ traffic violations. A total of 423 delivery riders and 411 private riders in Da Nang participated in the study. The results show that attitude, perceived behavioral control, and perceptions of deterrence significantly impact riders’ intentions to engage in risky behaviors, with delivery riders being particularly responsive to law enforcement and penalties. To enhance policy effectiveness, interventions should employ tailored enforcement strategies that account for the unique motivations and perceptions of each rider group. For example, increasing the visibility and consistency of law enforcement could be particularly impactful for delivery riders, who are more sensitive to immediate deterrents. Policy adjustments should also focus on reshaping riders’ attitudes toward safety and adjusting their perceived control over riding situations. By tailoring interventions to effectively influence each group's behavior, we can ultimately reduce traffic incidents.