The enforcement is patchy. There are loads of cameras and they pick up some things like speeding or driving in bus lanes but not others live those you mention. I drive and cycle and driving in central London is an odd experience these days that seems almost stationary - wait at lights for a minute, roll a few yards at 15 mph, wait again.

Most actual cycle deaths seem to be people crushed by lorries when turning at junctions which seems more an engineering issue - the drivers can't see etc. than bad driving.

I think it's both.

The onus is on a driver making a manoeuvre to ensure that it is safe to do so, and turning left shouldn't just be performed blindly if the driver has restricted view around their vehicle. However, there's a lot of poorly designed junctions as well.

I believe that one way to improve the problem of left-turns is to have traffic lights that enable cyclists to go first, or allowing cyclists to treat red lights as "give way" signs or turn-left-on-red.

There's also the question of whether we should allow vehicles to use public roads if they have known "blind spots" that drivers are not able to resolve by moving their heads.

Personally, I'd like to see a far more serious attitude to road/traffic safety. When there's a fatal collision, the junction/road should be closed to motor traffic until the junction can be made safe (e.g. adding a separate cycle lane or amending the traffic lights). However, motornormativity suggests that it'll never happen.

I'm not sure with the trucks. My guess is requiring cameras that provide a view of the problem areas might be the thing, possibly with some AI that detects cyclists and the like. I think a lot have warning signs on now for cyclists. Personally I never stop anywhere near them and treat the red lights as kind of give ways.

I'm not sure the highway code rules are that appropriate for places like central London. I tend to treat the whole place like a pedestrianised area - not worrying too much about road signs but giving way to pedestrians.