A few months ago by us BT Openreach decided they needed to do some work right next (within 50 metres) to a busy traffic light controlled junction, although they were working on the pavement and their vans were parked off the road the other side of pavement they coned off the road down to one lane and installed their own traffic lights which were in no way synchronised with the main lights (actually it would have been pretty impossible to synchronise them), nothing was happening in the lane they coned off, I think they refer to it in H&S speak as a 'buffer' zone. The result was absolute traffic chaos for 12 hours, where people going across main lights on green were immediately stopped by BT lights so junction was blocked, and people getting a green light from BT were immediately stopped by main traffic lights - blocking up the single lane that was available, It took us a good 30 to 40 minutes to get across junction and traffic must have been backed up for miles in every direction. I would be happy for contractors to have 15mph limit past where they are working and portable speed cameras to enforce limit, but nowadays roads seem to get blocked off regularly even when people are working on pavement.
I know pedestrians have rights, but who walks anywhere these days anyway, and it would have been much easier to re-route (very few) pedestrians than logjam the traffic on two main roads.