"Dave Larrington" said:

I think Rotherhithe Tunnel is legal for cyclists
(somebody correct me if wrong) but it is very
polluted.

It is indeed legal for cyclists, and is probably the only place I would ever
ride on the pavement rather than the road. Though given the choice I
wouldn't ride there at all...

It's legal. It doesn't feel *too* dangerous.

However, the technical term for the whole experience is ****ing,
****ing, ****ing horrible. I really wouldn't consider it for a commute.

John