English: The Airside Road Tunnel at London Heathrow Airport, looking east from the west portal. The wall at centre divides the eastbound tunnel (brightly lit, left) from the westbound tunnel (dimly lit, right). The dividing wall holds up the aircraft stand that sits above the west portal structure. The rectangular (cut and cover) tunnel section in the foreground is 60 metres long; beyond that is the pair of bored tunnels (8.1 m internal diameter). The westbound tunnel turns out of sight about 250 metres away from the camera. Photo taken during final site tests in December 2004; all the lights were on in the eastbound tunnel as a soak test for the lamps in the entry zone lighting.