Around fifteen years ago, I read as a child with fascination an account in Scientific American about an automated highway project where sensors were to be placed every few feet on the road, and cars would follow them, until a driver retook control at the end. I imagined a future network of roads in which cars read from sensors to determine where they were, and was kind of saddened that governments didn't immediately start putting these sensors into highways. This is such a cooler solution, one that doesn't depend on a parallel development of infrastructure, one that would presumably take lots of bureaucratic steps that are naturally associated with usage decisions on publicly owned land (which makes sense).
What this reminds me of, rather spectacularly, is that if one method of getting to your solution fails, either because those sensors didn't work out, or the bureaucracy didn't, if you come up with a solution, and say "oh by the way I did it already", it's a lot harder for anyone to ignore it.