My advice is not to commute by car, if that's what you were thinking. My time estimate earlier assumed you'd be going by train. There are several advantages to using the train: (1) it's usually faster if you live and work not too far from a station, (2) the commutes *can* be grueling (not much worse than NY, LA, or SF, though), and (3) you can use the travel time to read, chat with friends over email, or just veg out. I've been here 9 years and only once did I ever drive a car (I rented one for a vacation trip and, in retrospect, regretted it). The trains may be crowded at times but they are fast, convenient, and reliable.

If you *must* drive, you're lucky to be working in Yokohama. Depending exactly where your workplace is located, you can probably find a commute path by car that will steer you clear of the bulk of the famous Tokyo traffic jams. But you don't have to go "rural" to live in Yokohama (or nearby Kawasaki).

Interestingly, traffic (from my pedestrian viewpoint) seems worse on weekends than during commute hours. My guess is that's because everyone is on the trains ;-).