Driving to work takes effort: concentration on the road and arriving safely. When one arrives at work this level of effort and concentration continues into the work of the day. At the end of the day, that effort and concentration continues as one drives home again. From leaving home to returning home again, one is expending effort and concentrating. The working day is extended as a result by the work that it takes to get to and from work.
Going to work by train or bus, if undertaken in the right frame of mind (and in the right circumstances: on trains and buses that are not overcrowded or uncomfortable) can (or perhaps should) be an extension of the leisure time one has at home.
