There are a lot of people who are naturally quite lazy and selfish. I can be one of them. If I can drive somewhere and do the chore , cutting down travel time I may choose to drive. On the other hand if I'm not working, like now, I will walk or cycle. I'm not so time poor right now and its getting my exercise in, in the absence of a gym etc. If I was working and time was precious with school drop offs etc I might revert. Im sure this applies to many others.