TandemJeremy, what you need to take into account is the "cost per additional mile" once you accept that you own a car.
My car insurance is fixed unless I do over 15,000 miles. So is VED and MOT. Servicing is also 15k or 12 months. So you see that the cost per extra mile is less than you expect.
Now of course you have to cost up the "car free life" versus the "with car life". Owning a car is an expensive club to join, but once you are in it the extra cost per mile is less than you calculate.
That said, I genuinley crave a society that enables me to share access to my expensive metal box sat on my drive and enable cheap public transport as an alternative. In 2010 it isn't there.
Let me give you an example. We live in Leeds. 300m from the nearest train station that goes straight to Meadowhell shopping centre in Sheffield. for the four of us (2 adults 2 kids) it was approx £15 return on the train and is approx a 50 minute journey. In a car it is 30 mins and costs £7 in petrol (at todays costs). I really want to use public transport. But in most of this country its crap and expensive.