Bristol pedestrians to have immediate priority over vehicles at traffic light crossings

This is going to make some people cross.

What is the current behaviour (I don't know how these commonly work in the UK - I do know that often you seem to have to wait for some time...)?

I could imagine we have either "unless drivers have had at least x seconds of green, do not change signals" or "if a certain volume of traffic is detected, don't change signals (unless y seconds have passed)".

Conflicts over pedestrian crossing signals often make me wonder if the question should be "why do we need a signalised crossing here anywa?" Often the answer seems to be because "we are trying to combine 'flow' for motor vehicles with lots of pedestrians e.g. run a traffic artery / distributor through somewhere we also want to be a 'place' "  So effectively the issue is we've allowed too many motor vehicles through here / set speed limits too high / the road is too wide.

This is very common in the UK, due to the way our roads have "evolved" and we expect them to be multifunctional.  But that ends up being inefficient for drivers and unpleasant for pedestrians.  As opposed to the kind of organisation seen eg. here.

Of course, that's historic network-level problems and those can be several magnitudes more than 20K to fix!

This is such a no-brainer it really should be standard practice worldwide. But as the world is, I wonder which will be seen first; this or a train station in Portishead?