I think the road infrastructure pales in comparison to the subway/rail system. The volume of people it moves is incredible. Also remember that it's all built in an earthquake-prone area!
I didn't even bother getting into the rail system, since I assume everyone realizes how advanced it is. I really wanted to put this in though: I've watched Shinkansen pull into the switchyard at night to "go to bed". It's quiet. Here's a bullet train, cruising into a rail yard pretty much in the middle of a neighborhood, idling along after midnight, and you only hear a very muffled motor as it glides by. Compare that to America, where our trains seem to be built solely to meet basic load requirements, and where they honk four times (as long or short as they want) before every crossing that's not guarded with quad-gates.