New TfL's HGV's can't see you for s*** poster

True, good point. I reckon though that if a slower limit is in place, even if the traffic is moving slower than it, the lower speed limit just implies a more "drive safer" kind of attitude? I know that if I drive through a 20mph school zone, you definitely tend to be checking about you mirrors and generally driving in a more controlled manner, just in case.

Cyclists are usually the fastest vehicle on the road during rush hours, and they are getting killed by vehicles manoeuvring badly, not going too fast.