Objective: This study aims to evaluate vehicle safety in highway work zones by analyzing collision risk using vehicle trajectory data collected from these zones. Methods: First, vehicle movement within the work zone is monitored using UAV technology, and vehicle trajectory data along with traffic flow characteristics are extracted using Tracker software. Next, a risk assessment method is proposed that comprehensively evaluates both the likelihood and severity of vehicle collisions in the work zone. Finally, the distribution patterns, spatial variations, and influencing factors of collision risk within the work zone are analyzed in detail. Results: The analysis reveals that the collision risk for lane-changing vehicles predominantly falls within the range of 0.3 to 0.5, higher than that of straight-moving vehicles, which is concentrated between 0.2 and 0.4. This highlights the elevated risk associated with lane-changing behavior. Similarly, the mean collision risk for vehicles in the warning area, transition area, and buffer space are 0.155, 0.207, and 0.252, respectively, showing a progressive increase in risk across these areas. Further analysis shows that the correlation coefficients of speed, speed difference, and acceleration difference with vehicle collision risk are 0.026, 0.305, and 0.698, respectively, indicating a significant positive correlation. Conversely, the correlation coefficient of displacement difference with vehicle collision risk is -0.281, demonstrating a significant negative correlation, which is significant at the 0.01 level. Conclusions: The methodology employed provides a detailed quantification of collision likelihood and severity, offering a comprehensive analysis of vehicle collision risks in work zones and their spatial distribution characteristics. It also explores the relationship between these risks and vehicle motion parameters. The findings offer a scientific basis for identifying high-risk areas and formulating targeted safety improvement measures. Furthermore, the study provides crucial technical support and decision-making guidance for enhancing traffic safety in highway work zones.