Or , a side button BOOST button. my favorite is to click light on normal , and to have little momentary button that boost into hard drive any time i want, or even if i just want to press a button out of boordom. with the same button i can get a "hey You" flashing going for a few seconds manually.
but no way without some actual curcuit flashing somewhere, to do the "traffic hazzard" , which i agree doesnt have to be obnoxious, but it needs to change to be seen better, or to be seen among a wash of headlights or other illumination. The freeway dont kill me hazzard blinker. which might be best as red flashes or flares, or reflectors, but if there is nothing else like you are not in your own car even, only have your EDC, but are still roadkill freeway meat with no shoulder, or some emergency.
say your the one person who instead of filming others driving off the end of a bridge during an apocolyptic eathquake , you shoot off a warning to that person about to drive off to thier doom. , would it be usefull if you could just set it and forget it . rare situations, but possible.
"honey what is that light flashing there ???? , OHHHHhhhh AHHHHHHHhhhhhhhhhhnnnn. .. ."
http://www.youtube.com/watch?v=7Q0_Z-9839c
and who would want to stick around, with the structure comming undone under you. just leave a hazzrd beacon? and get yourself to a safer location?