It's Upper Thames Street, one of the busiest roads in London
which, before we had a Mayor, was a free-flowing route. Both
Mayors have damaged the route and now half of the road has
been allocated to the Cycle Superhighway. Result, lots of
stationary traffic emitting fumes.

Of all the 20 places listed, only Wallington surprises me. For
the rest it's all very simple. Count the number of traffic lights
of all types in the area, then do the research and find how
many lights were there twenty years ago. Then do a similar
comparison of the phasing of the lights. There's no mystery
about why London now has a severe air pollution problem.