I know this is an old thread, but it’s been police policy in Washington DC in recent years that cruisers must have their smaller flashing lights on at all times (usually white, although I think I’ve sometimes seen blue), to increase the visibility of the police presence. No sirens except in emergency, and fire/ambo does not follow this policy.
My mom is a paramedic and that’s similar to what she says.
Good rule of thumb. Retired EMT here.
You’re laughing (so am I), but it could happen. 
A patient in good enough shape to kick your collective asses will probably not be requiring transport with lights and sirens.
With all due respect, I disagree. A handful of times we had either a town cop or NY State Trooper riding with us. The patient was handcuffed to the stretcher. Both hands. One to each side rail.
Believe me, this was because they were both in need of medical transport AND in a position to injure or kill the medical crew.
Psychological emergency. Drunk. Out of control on drugs. Pick any one, because I’ve either driven or been in the back for all three situations. All three required handcuffs and police presence.
Not if they’re impaired… In NYS you need to transport if:
patient is under 18 y/o without a parent or legal guardian
patient is impaired
patient is unconscious
patient is unable to contest
the situation is escalating and there is risk of injury to personnel or patient…
And, in the situation of a suicide, which this was, and the person lost a lot of blood, (and was drunk) you need lights, we also believed he may have used PCP, though not sure, and we all know what that does…
In case of zombies, break glass for chuck norris…
and in NYC, if you do not pull over for a firetruck with lights and sirens, they are allowed to plow through you…
ambulances and police cars don’t, mainly because they will get just as damaged as the car…
Unless you’re talking about a swat tank, but don’t even get me started on those…