Because of the high salaries, the cosmopolitan atmosphere, and the sheer amount of things available for you to do.

But trust me, I am not the only person living in London planning to retire somewhere else.

Don't delude yourself, London isn't a modern city, it simply hasn't got the infrastructure in place to make it so.

As for the dirt, I have never found diesel dust and rubbish to give a place "character". A lot of London is a dirt, I have gotten used to the London stench but every time I go away and come back the diesel stench hits me again.

I live in London, and the only reason to live in London is to get paid enough to get out of London in the summer and go somewhere a little bit less dirty and crowded.

London’s infrastructure is wholly inadequate and can’t accommodate the number of people that reside in it. London is full of little old houses that should have been replaced with modern apartment buildings long ago, the same goes for its transport infrastructure, the road system plainly doesn’t work and should have been updated 30 years ago, the underground system, it is dirty, inefficient, uncomfortable, and there’s nothing 21st century about it.

London has a lot to learn from many of the world's cities.

Yep, it's also their mass, not just their emissions, that causes problems. For example, striped crosswalks are safety devices. When you see one gradually fade to invisibility over time, it's because of the mass of the vehicles passing over it. Your tax dollars getting wasted by the weight of Chelsea Tractors and other oversized nuisances.

Mixing congestion pricing with pollution control threatens the argument for the former.

HOV lanes might be more susceptible to a hybrid model (pun intended) if they take into consideration both mileage and occupancy. For instance, if you set the HOV lane to 40 mpg per person, you would be able to use it solo with a high MPG car, with two people in any moderately efficient car or light truck, and with three or more people in all but the most egregious offenders.

I don't think you can take occupancy into consideration with congestion fees. And, sorry, a single person in a Prius traveling for free is not good urban policy.

Still - wow! What a difference it would make if New York's officials were talking about these issues in this manner. Let's get charging in place first, then we can build on that, huh?

http://transport-link.com/costs/nyccost2000.html#table

Hopefully this doesn't boost the case for a free ride for low polluters in NYC area tolls/HOV lanes.

In point of fact, the CO2 is not strictly classified as a pollutant, but an emission. One of the regrettable aspects of the Congestion Charge is that heavily polluting powered two-wheelers have been encouraged (through exemption from the charge). These emit less CO2, but - surprising but true - emit orders of magnitude more harmful pollutants (particulates, NO2, SO2 etc.) per mile.

Ideally, the Congestion Charge would target congestion, CO2 emissions, and air pollution - leaving only public transport, walking and pedal cycling exempt. Still, the Mayor's announcement is a step in the right direction.

I can see scaling the charge based on vehicle size -- but to make it compeletly free for the "least polluting" vehicles subverts the purpose.