I like that idea! Gonna buy a bunch of those, amplify their signal and spread them throughout the city I live in. That will ensure that there's not going to be a single crappy autonomous car being beta-tested in my vicinity!
Another idea would be to just throw them right in front of an autonomous vehicle at full speed. Let's test those brakes!
(sorry, but the original idea is just so ridiculous that I am incapable of responding in a non-sarcastic way to this...)
I imagine phones will serve that role eventually. GPS chip accuracy is improving constantly and could be accurate to within a foot in some phones in the next year [1]. Google Maps / Waze already do something similar with predicting traffic times based on phone data (and other sources). GPS accuracy currently may make an individual's location slightly harder, but path prediction may help. (And, of course there are privacy concerns to consider.)
So if you're homeless and can't afford a phone or if you forgot yours at home or if you got pickpocketed... you can expect to get hit by a self driving car?
That sounds like something that will immediately be abused for tracking people, and an over-reliance on it may make it more dangerous for people not carrying one (don't want to, can't afford, signal blocked by item/clothing, simply forget etc.).
Roads are generally marked, and often have elements embedded in the surface (e.g.
[1]). As self-driving cars become more prevalent, I don't see why you wouldn't adjust new/replaced markings to be something more readable by those vehicles. It obviously can't be the only signal used (because it's infeasible to change everything immediately, not all roads are marked, and wear/damage may make them unusable) but it may help improve reliability/accuracy.
> This is about as feasible as putting smart chips in all roads so that cars know where the lanes are.
Lanes are marked, usually. So why not embed something like an UV/IR-only color pigment in the lanes? Invisible so it doesn't affect human drivers but can easily be picked up by cameras.