The ninth AI City Challenge advanced real-world AI applications in transportation, automation, and safety, attracting 245 teams from 15 countries—a 17% increase. Featuring four tracks, the 2025 edition introduced challenges in 3D multi-camera tracking, traffic video question answering, warehouse spatial reasoning, and efficient fisheye camera detection. Tracks 1 and 3 utilized synthetic data from NVIDIA Omniverse. The evaluation platform ensured fair benchmarking with submission limits and held-out test sets. Public dataset releases reached over 30,000 downloads. Final rankings, announced post-competition, highlighted strong global participation and new benchmarks across multiple tasks, driving progress in intelligent visual perception and reasoning.