UrbanFlow AI
Built at Meta Global AI Developer Hackathon · Oct 26, 2026 · Remote
Over 80% of municipal traffic signals around the world still run on rigid, pre-timed schedules designed in the 1970s. This outdated infrastructure costs the global economy over $88 billion annually in wasted fuel and lost productivity. But the far more tragic cost is measured in human lives: emergency responders routinely find themselves trapped at red lights while empty cross-streets get green time. In cardiac arrest, stroke, and severe trauma emergencies, every 60 seconds of transit delay reduces patient survival rates by 7% to 10%. Optical sirens and strobe detectors fail at distance, create severe blind spots, and cause dangerous secondary collisions when cross-traffic is caught off-guard. UrbanFlow AI solves this crisis by pairing real-time adaptive traffic intelligence with an uncompromising, mathematical safety kernel. Rather than theoretical simulations, UrbanFlow AI is built as an industrial-grade digital twin platform. In a live browser session, it runs dual 8-lane intersections simultaneously—feeding the identical pseudorandom vehicle arrival seed into both a legacy fixed-time controller and our adaptive controller. Judges and city planners can see the proof side-by-side in real time: adaptive queue-pressure balancing slashes average delays by up to 24.8% and eliminates queue spillbacks, while discharging more total vehicles across every single tested traffic demand scenario. Core Architectural Innovations: 1. Microscopic Multi-Class Physics Engine: High-fidelity Intelligent Driver Model (IDM) car-following physics across 8 approaches (through/right lanes and dedicated left turns) with 5 vehicle classes (passenger cars, buses, delivery trucks, bicycles, and emergency vehicles). Running at 10 Hz inside a background Web Worker with zero-copy binary ArrayBuffers, it delivers 60 FPS graphics without blocking the user interface. 2. Single-Writer Deterministic Safety Kernel: We believe AI should never directly command physical city infrastructure. UrbanFlow enforces a strict mathematical boundary: heuristic algorithms and Meta Llama models generate advisory requests only. Only our deterministic Safety Kernel can mutate signal states, mathematically enforcing 6 critical invariants on every 100ms tick: minimum green (4.0s), mandatory yellow clearance (3.5s), all-red buffer (2.0s), anti-starvation limits (120s), and absolute phase exclusivity. 3. Cryptographically Authenticated Emergency Vehicle Preemption (EVP): Real-time V2X distance tracking with constant-time HMAC-SHA256 signature verification, single-use replay nonces, and storm-guard rate limiting. The system enters a PRECLEAR state through safety buffers and awards a conflict-free EMS green wave, allowing ambulances to cruise through intersection boxes without stopping. 4. Edge Gateway & Cloud Telemetry: Powered by Cloudflare Workers and MongoDB Atlas for sub-10ms operational queries, combined with PySpark Structured Streaming for sliding-window anomaly analysis. UrbanFlow AI proves that municipal infrastructure can achieve transformative efficiency without ever compromising public safety.