Also I wonder why a developer opposite Lambeth North station has been allowed to close a bus stop and bus lane for months? If you were redeveloping your house, do you think they would allow you to have a skip and a van parked in that space for ever so long? This is also causing congestion every single morning I pass by or rather get stuck there. Just after that junction buses also get stuck because there is not enough space for them to squeeze by another development. Lots of things contribute to jams, not only building cycle lanes.
It is intensely frustrating that developers can shut roads for years but we just appear to accept it, as if it's a natural part of life like the weather. I also believe the traffic is related to E&C, as the problem started when the works started at E&C. I'm not convinced the traffic will return to how it was when the works end, but time will tell.
In relation to the hatch marked box, I have asked Southwark to consider a 'keep clear' sign for the junction of Hatfields and The Cut, as it's constantly blocked, even out of rush hour. We might need to ask for more of them on other roads, but it will probably increase congestion (I'm not sure of the research in this area, but keeping a junction clear in one area probably causes a tailback elsewhere). A hatch marked box for Blackfriars would be via TfL, but I'm not totally sure it's needed as the traffic doesn't tend to particularly block that junction.
Ultimately we need less cars in the area. I had an interesting experience at the weekend. I drove to West London on a Sunday evening and the traffic heading west was terrible, which is likely to be all the people heading home after a visit to town. Our area however was dead with very few cars (though plenty of people). It's almost like the people driving around here are not locals, but people who live on the outskirts and insist on driving their cars through London.....
Zoe, I suspect you are right - East Walworth ward at the Elephant (largely SE17 not SE1) had only 27% of households having access to a car in 2011 (quoted in this downloadable 6.4Mb PDF) whilst Chaucer and Newington ward rates were 29% and Cathedrals 31%. The average for Southwark was 41% and the average for London was 58%.