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Front Brake Lights Could Drastically Diminish Road Accident Rates
(bioengineer.org)
This is a most excellent place for technology news and articles.
There's a programmable flasher relay that does exactly this. It's specific to certain Toyota/Lexus and Subarus from the 2000s to mid-2010s, but it's something. I have one in my 2008 Sienna - the "emergency flasher" part is programmed to strobe, kinda like a tow truck. I like it.