No, not just that. Two reasons.....
1) Can I be permitted a computing analogy? In the early days the computer companies were looking for a 'killer application, something so good people would buy a computer just to run it. It turned out to be spreadsheets. (exciting aren't they

)
Now London has several 'killer apps'. People will always make the effort to get to central London, because it has several things you don't find elsewhere in Britain, even the world. I'm talking about Oxford Street, the City, the Legal quarter etc etc etc. A city law firm won't give up it's prestigous W1 address to move to an industrial estate near Slough, nor will shoppers swap Regent Street chic for the Tesco extra at Beckton, nor will doctors want to lose the prestige that goes with a Harley Street surgery. People will either cough up or switch to public transport.
Other cities just aren't like that. They *need* to attract people in. I happen to like my city centre, but I could buy everthing I can there in Asda, Currys and Homebase if needs be. Too much employment is already based around the outer ring road and beyond, in public transport UNfriendly locations. How will congestion charging help to reverse this trend, please????
2) Car ownership in the rest of the UK is much more spread across the social groups. I looked at the cars on the way into uni this morning (walking I might add!!). At a guess over half of them were over three years old. Most were small to medium sized. Car ownership isn't a rich mans luxury up here. You should see the number of newspaper adverts 'Own transport essential due to location....Pay? (six quid a hour if you are lucky)
please listen to us........YOU ARE NOT GETTING A TRUE PICTURE LIVING IN LONDON.
Depends what you mean by too many. The vast majority of car drivers don't own a car to look cool. Some do, to be sure, but they give the rest of us a bad name. But in general PEOPLE OWN CARS BECAUSE THEY NEED THEM,AND THEY USE THEM BECAUSE THEY NEED TO.
It follows then, the only way to reduce car usage (I personally don't see anything wrong with people *owning* a car as long as they only use it when they need to) is to reduce the NEED to use a car.
In short, it means town planning with the reduction of car usage in mind. And it means young couples thinking about where they live *before* they walk down the aisle.