Three small examples:

G/F and I will have walked Offa's Dyke Path - 177 miles through rural/semi-rural Wales/Marches (and hopefully will go on to complete the Wales Coast Path) by using public transport. I have climbed all but four of the South Wales mountains using public transport (and I have no doubt I would have found a way to the other four if a lift hadn't been offered - I'm not anti-car!). I've visited hundreds of remote sites using public transport.

I walk to the railway station (25 mins) from my house every morning and then catch a train to where I work. It's a total commute of 35 minutes that a car would do in 20-25, depending on traffic, so I'm aware its slower.

I do my shopping in the Co-op and greengrocers down the road, rather than an out-of-town supermarket.

Mustard is quite right that people as a species are resourceful, so why not turn that into trying to cut down on car use? As in my examples above, it's not an impossibility.

Just to clarify, I'm not opposed to cars at all. Nor do I expect to convert anyone to my way of life, it's my choice. I grew up in a rural community, so I do appreciate that it is very difficult to do without cars in such areas. But what I am opposed to is the hundreds of thousands of (mainly) urban journeys (out of town supermarkets, local shops, school) that could be made without such reliance on cars. Car-sharing could be used much more proactively, most cars have one person in them. Local bus routes, bike riding and walking can all play a bigger part. It would help this nation's chronic obesity/diabetes as well as the environment.

I think many people are acutely ignorant of the public transport available in their areas, because they've never needed to consider it. That's not a criticism, just an inevitable truth. There are brilliant websites detailing bus routes, timetables, etc, that can help you plan journeys using the public transport system.

But what all this does take is effort and planning. You might have to get up a bit earlier, you might have to shop more frequently rather than doing one enormo-shop. Even if you make one or two journeys less by car, it all adds up. These are not impossible things, honest!