Paul Terry wrote:

In message , Roland Perry
writes

I'm astonished that there's so much room! Must have a better look next
time I'm there. All I remember is the loading gauge and a general
feeling of claustrophobia when approaching even in a car, that made me
choose the main tunnel instead.

I think the part that is currently used is only the upper deck shown in
the ATS cross-section (2642mm high) - IIRC it is a couple of metres
above the main roadway, as shown.

It looks as though they are intending to put the bottom pair of tracks
on the lower deck, which was originally the pedestrian route through
from the Bath Road when the tunnel opened in 1955.


As a regular visitor to Heathrow (eight times in the past month) I
wonder what assessments have been made of the additional road
congestion that will be caused by closing the "taxi tunnels" to cars.

It is some time since the taxi tunnels were used only for taxis (and
cycles) because the road layouts were changed a few years ago to allow
them to be used by cars. There are now three lanes into the Central
Area for cars and three lanes out. This proposal will reduce that to
two because the taxi tunnels will be used for ATS vehicles.

If ATS results in a reduction of road traffic through the tunnel
system that is greater than the capacity lost by closing the taxi
tunnels to cars, all will be well. But I cannot see that happening,
and there will be horrendous problems while ATS is constructed.

I must admit a personal interest, in that the taxi tunnels form part
of my alternative routes in and out of Heathrow that miss most of the
congestion most of the time.