As hazard warning lights are used to warn of a hazard, I feel they should flash at, say, twice the regular frequency of a standard indicator. It's not unusual to be able to see only one side of the car and this would facilitate differentiating between indicating and a genuine hazard.
Some cars' indicators flash faster when a bulb has gone, but bulbs blowing is rare.-- paraffin power, Nov 02 2004 Fast flashing can also indicate a flasher that is nearly worn out, which is also rare.-- swamilad, Nov 02 2004 Yes. Yes. Yes. For exactly the reason you state. The number of times I have slowed to let someone out into the traffic, only to find they have their hazards on and I can't see the other light.
Maybe a double flash followed by a normal time interval? Everything else seems to be computer controlled these days, why not indicators?-- egbert, Nov 02 2004 Yes. And <rant> how about "I know I'm parked on double yellows on a blind bend, but I've switched these flashing lights on so it's OK" lights too? This could take the form of a big flashing arrow saying "book me, I'm a fool."</rant>
Croissant.-- david_scothern, Nov 02 2004 [ds] Some people treat them as a cloaking device.-- paraffin power, Nov 02 2004 Much needed. +-- Shz, Nov 02 2004 Sigh. I've meant to post this idea for ages, only to find it's already there. Bun [+]-- TheLightsAreOnBut, Jul 16 2007 Why not use Morse code to spell the reason for the stop?-- AbsintheWithoutLeave, Jul 16 2007 "I'm very sorry, sir. I was too busy deciphering the Morse warning to notice that the traffic had stopped, and I ran into your car. You'll be pleased to know that the traffic was stopped because of a broken-down lorry, though... I just need to go and code my own hazard lights now. Can you remember the Morse for c?"-- TheLightsAreOnBut, Jul 16 2007 [d_s] - I was told by a pleeceman that using your hazard lights while parking on the double yellow is a driving offence and gets you points on your license, whereas just parking on the double yellow is a parking offence and will only get you a fine.-- wagster, Jul 16 2007 Is it only obvious to me that it should transmit the SOS code? +++---+++-- Custardguts, Aug 18 2010 what [Cg] said... well not really unless there was an in-car emergency, but have the turn signals flash in between the 4-ways.-- FlyingToaster, Aug 18 2010 Related idea, put the hazards on a separate battery backup, so that if your car dies due to an electrical problem, they still work.
But I agree, flash speed isn't the best, since that already varies between cars, but a double flash or something would be distinctive.-- MechE, Aug 18 2010 //it should transmit the SOS code//
No it shouldn't. There are many valid reasons for declaring your vehicle a hazard, not all of them requiring emergency assistance.-- Tulaine, Aug 18 2010 random, halfbakery