i carry on as normal and, if it is safe to do so, pull over
otherwise they have plenty of places where they can overtake and they should be judging when it is safe to do so
i'm not like a lot of peole who, when they see a set of blue lights in the background just stop in the middle of the road like usless cunts

and gridlock the place
i won't try and get in the way deliberatly, nor will i try and obstruct their path, but soemtimes they do drive as if it's a matter of life and death when they really just want to get to their doughtnut
one other thing i have noticed is that, as of late, they put the lights on, but don't use as much siren u nles it's at a junction, where as abulmances and fire engiens have them on much more often, any reason why?