Trust the Japanese salaryman on this: public transportation is not a panacea for avoiding accidents caused by drowsiness. You have to be able to get to the train station and from the train station to your house, all without killing yourself.

I have become a frequent face at a local hotel because I was so tired I did not trust myself to do that. (The project at issue is mostly done. Thank God.)

(Quick sidenote: Five minutes before checking into the hotel to avoid killing myself walking down the street, I was being paid time-and-a-half because my workplace apparently thought that my presence was adding value. Some of you people reading this will eventually be engineering managers. If you ever are, prior to ordering Heroic Efforts (TM), please consider whether you really want me working on a production system in that state.)