I seem to remember cycling on the Westway a couple of times - just one junction, but I couldn't see any way of avoiding it. I can assure you it wasn't by real choice.
Gliddy you are indeed a very brave man. I knew somebody who used to cycle on the A13 from Central London, out across the Canning Town Flyover and past Beckton. The dude was mad. I say I used to know him as he left the company, didn't finish up under a bus thankfully
