A Hacker News user recently shared **nexttrain.london**, a 3D visualization project that tracks London trains and airport-bound transit in real-time. Built using the deck.gl framework and Cloudflare Workers, the tool fetches data from TfL and National Rail APIs to display live train movements across a 3D map of London. The project received significant community engagement, with users praising the technical ambition and the "vibes" of the visual experience. However, feedback highlighted several areas for improvement, including rendering glitches (such as incorrect z-buffer layering), missing rail branches, and navigation constraints. Some users requested a more "free-form" camera view, while others suggested adding immersive elements like satellite imagery or better 3D depth to distinguish between underground and overground lines. Creator `mgranados` actively engaged with the feedback, acknowledging the technical challenges of handling disparate transit data sources and promising to refine the rendering and UX in future updates. The project has sparked interest as both a technical demonstration and a novel way to view city infrastructure.