Not to mention that passenger miles are substantially more efficient in cars - You drive (almost, given the amount I get turned around) directly on the shortest

Not to mention that passenger miles are substantially more efficient in cars - You drive (almost, given the amount I get turned around) directly on the shortest route to your destination, while a large percentage of mass transit system rides involve a transfer. Probably not a 10x, probably not even a 2x, but I did the numbers on my commute that was nearly-straight and still found I was going 20% farther to reach my destination by mass transit, because the time-efficient route required going backwards.