Well rules of the road, Doug. Don't tell the cops but I generally break the speed limit somewhere or other most times I go out in my car. In 55 years I've been "done" just four times. The speed awareness course was hugely entertaining. The guy who ran it was a cardboard cutout of Dixon of Dock Green, knee bends and pelvic thrusts included. I see plenty of drivers speeding up to get through lights on amber, dangerously cutting corners, displaying terrible road positioning when turning right, ignoring pedestrians who are trying to cross, tailgating, undertaking...

Cyclists are easy meat. They are flesh and blood out in the open, they can hear you shout, they will always come off worse in any accident with other vehicles. Shout at the blatant rule-breakers by all means, but, generally, you can't shout at the bad drivers. Their windows are up, they can speed off, they're often elderly, etc. and there are plenty of 'em.