It wasn't supposed to be this way
So the Enviros (who pretty much run the CA government) have for years been decrying the fact that too many cars in CA have but one passenger. Fair enough. Along comes something that could drastically reduce the problem, but wait! Turns out that same CA government has been earning their pay by outlawing just such a scheme. D'oh!
The obvious fix would be to rescind that law, but it's just so much easier to make new laws, like making it illegal to drive alone (unless you have the right connections of course).
;-/