getting on traffic detail / fire police duty is what saves everyone else on the scene,...but it is a great opportunity to get your body run over or your car smacked.
when you are parked nothing beats a plain old kojak style blue light plugged into a small jumper pack, so you can shut down and not waste gas. 360 degrees is really needed (like temporarily stuck to a screw or a platform on the subaru cross bar), and a cheap old style spinner does the trick. Particularly if you are stuck on a intersection.
White, Red vs. Blue, (white or red strobes I think confuse drunks, ...US DOT probably has a paper on that, which I am not going to dig up).
people know what it is and what blue means, even drunks see the blue and they put their foot on the brake and avoid hitting you.
Vs. what happened to those NYS troopers years ago which caused them to get the rear facing blue lens, ...only after 2 or 3 got rear ended in a few months.
I remember their union did not want its members to pull people over where another car could line up behind the red lights until the lenses were changed,...and they got the fire extinguisher mounted on the gas tank. (I guess it would still suck to get rear ended on the thruway at 70mph, but it was a start for lower speed crashes,...too bad the technology did not get into regular cars).
and this is as great as things can be, no warning signs out, but at least a DOT truck showed up, so it can get rear ended and not some poor guy in a subaru.