OTOH, a limit of 70mph might be too high for my granny. And 100mph is a joke for somebody with racing experience. Who do you design for? You are very responsibl

OTOH, a limit of 70mph might be too high for my granny. And 100mph is a joke for somebody with racing experience. Who do you design for? You are very responsible and everybody should behave like you; but what if you get diminishing safety returns when driving lower than 90mph because your reflexes are good enough? Should you get fined for driving 90 then, and my granny (who can barely handle city traffic) is not fined for driving 70 while endangering other people? Edit: Forgot to add my favorite solution: Add a very high, hard speed limit (130mph?) on all streets, and let traffic signs serve as recommendations. Obviously, also limit to walking speed in neighborhoods where kids play in the streets, or city centers.