There are circumstances where police and certainly emergency (fire, ambulance etc) vehicles can "break" the road rules.
In the case of the emergency vehicles, running red lights and weaving between traffic is necessary to save lives by avoiding delays.
Cops will need to "speed" and weave through traffic to chase criminals. They are not going to say "oh well, the limit is 60km but the bank robber is getting away at 90km so we can't get him".
Of course there are cases when cops break the rules without justification.