Any question answered...

What a lot of cyclists don't realise is that you can legally ride on the footpath by the river along the most congested stretch, and go under the bridges, thus passing all the stationary traffic.

Yup, although 95% of the time it's just faster on the road (even taking into account stopping at traffic lights). I'm not a fan of doing 20mph+ on a shared use path.

Of course, it was way way faster to use the path yesterday evening when it was near gridlock all the way from Millbank to Parson's Green due to a bus/lorry crash.