Why do emergency services not use bikes?

So this morning I got stuck being an ambulance, sirens screeching, desperately trying to push through the river of bump-to-bump cars on William Nicole. I have no idea as to the target of their final destination, but it occurred to me that the whole emergency services thing seemed a bit inefficient.  Here is someone that is 100% focused (hopefully) on getting to the scene of an accident, causing much frustration to themselves as well as fellow road users and though they are moving through the traffic, the going is actually still slow (you always get one or two folk that don’t move out the way). 

Where the need for an ambulance is without question, surely it’ll be more efficient (and possibly save more lives) if emergency services had a fleet of kitted bikes for “first on the scene aid”. So … take a bike (like a BMW F800ST / GS or bigger 1200GS); put a loud siren on it and fit it with kitted out panniers (you can fit a reasonable amount of medical equipment into 3 large boxes).

???