Cyber-physical systems (CPSs) in autonomous vehicles must handle highly dynamic and uncertain settings, where unanticipated impediments, shifting traffic conditions, and environmental changes all provide substantial decision-making issues. Deep reinforcement learning (DRL) has emerged as a strong tool for dealing with such uncertainty, yet current DRL models struggle to ensure safety and optimal behaviour in indeterminate settings due to the difficulties of understanding dynamic reward systems. To address these constraints, this study incorporates double deep Q networks (DDQN) to improve the agent’s adaptability under uncertain driving conditions. A structured reward system is established to accommodate real-time fluctuations, resulting in safer and more efficient decision-making. The study acknowledges the technological limitations of automobile CPSs and investigates hardware acceleration as a potential remedy in addition to algorithmic enhancements. Because of their post-manufacturing adaptability, parallel processing capabilities, and reconfigurability, field programmable gate arrays (FPGAs) are used to execute reinforcement learning in real-time. Using essential parameters, including collision rate, behaviour similarity, travel distance, speed control, total rewards, and timesteps, the suggested method is thoroughly tested in the TORCS Racing Simulator. The findings show that combining FPGA-based hardware acceleration with DDQN successfully improves computational efficiency and decision-making reliability, tackling significant issues brought on by uncertainty in autonomous driving CPSs. In addition to advancing reinforcement learning applications in CPSs, this work opens up possibilities for future investigations into real-world generalisation, adaptive reward mechanisms, and scalable hardware implementations to further reduce uncertainty in autonomous systems.