[reversecs]

one could also factor in time. At work your time costs money and if driving allowed you to spend an extra hour working, assuming you were paid hourly, you could work one additional hour. in the case of salaried perhaps you performance would rise.

but I don't really like the idea of sacrificing exercise for additional hours at work.

[jdietrich]

By the same token, you could factor in the costs of ill health and premature death due to a sedentary lifestyle. Commuting by bicycle is a very time-efficient way of getting cardiovascular exercise.