Vehicle stops represent one of the most frequent yet tactically complex interactions between law enforcement officers and civilians. Although often routine, they can escalate rapidly. This study investigated the role of situation awareness (SA) in police officers' decision-making during vehicle stops. Drawing on Endsley's three-level SA model and Huhta's seven police-specific SA themes, this study explored how officers perceive, comprehend, and project evolving situations. Using qualitative data from 49 interviews with Swedish police officers, this study identified key elements that influence SA, including time and distance management, partner roles, suspect profiling, environmental conditions, tactical options, ongoing self-assessment, and identification of dangerous objects. These findings highlight the significance of structured training, effective communication, and adaptive tactics to enhance SA. This study contributes to both theoretical frameworks and practical advancements by offering insights to inform evidence-based training and policy development aimed at improving safety for both officers and civilians during vehicle stops.