It's a think that has been in my mind for a while, and the recent government decision here in Cyprus to decrease fuel tax reminded me of it.
What's the maximum distance, on average, that people where you grew up and/or live are willing to go on foot before they decide to use a private car (or for countries were people are willing to use public transport, that).
I grew up in a village that was 3km across (it has expanded a bit since), and the culture there was that any distance over 300 meters was enough to justify using a car. So to go from my house and my cousins' house, someone would inevitably offer to drive me to and from there.
I live in Nicosia now, and I think people are willing to walk more here, but not by much. Maybe up to a 1000 meters.