Nasty, and probably quite dangerous when tired.

I would, and in fact when working at our base office do, choose a 2.5 hour cross-London train journey at twice the cost to avoid doing a 1.5 hour car commute. I made that decision after a narrowly avoided accident (avoided by the other driver's actions, would have been caused by mine) which resulted from me "autopiloting" because of the tiredness that amounts up with an early start and spending those 90 minutes trying to be attentive.

Neil