For anyone who has not driven through the small bore tunnels before they can come as a bit of a surprise ! They are alongside and just outside the main dual carriageway tunnel. If approaching Heathrow stay in the left-hand lane of the M4 spur round the roundabout at the tunnel entrances.
You can get a car through but it is tight both vertically and laterally. I wonder how many hit the sides on the way through. I would think even a Land Rover would be too high. It's amusing to take first-time visitors to Britain from the US through the outbound tunnel and comment on why cars are smaller over here !
I wonder what the procedure is for handling breakdowns inside them ! It must have happened.
If leaving T1 and going up the M4 spur I often find it quicker at busy times to take the slip road round directly into the small tunnel (avoiding all the traffic lights in the central area), you have to go up the slip road at the other end to the perimeter road and then round past the Pink Elephant entrance and back down again, but it can still be quicker.
Correct me if I'm wrong, Heathrow historians, but do I recall that some years ago the east side small tunnel was converted into an empty taxi-only entrance from a taxi holding area where the Park One car park is now, through to the central area, and the west side small tunnel was the only one for foot traffic and cycles ?
By the way, again correct me if I am wrong but the "free London Bus" facility from the Central area to outside the airport appears to be completely unpublicised in the airport, and if you are not "in the know" you can end up unwittingly paying a fare.
Last edited by WHBM; 3rd May 2006 at 14:33.