The Dartford Crossing carries the M25 over the River Thames between Dartford in Kent and Thurrock in Essex. It comprises two road tunnels for northbound traffic and the Queen Elizabeth II Bridge for southbound vehicles. Completed in 1991, the cable‑stayed bridge was Europe’s largest when built; its central span stretches 450 m and sits 65 m above the Thames, with steel pylons rising 84 m above 53 m concrete piers for a total height of 137 m. The crossing forms part of the A282, the only fixed road link east of London, and carries about 150,000 vehicles each day. Because of high winds, traffic can be diverted into the tunnels, and drivers must pay a toll (the Dart Charge) to use the bridge during peak hours.