Michael Bloomberg is promoting a congestion charge on vehicle use during peak times in New York City to reduce traffic and generate revenue that would go towards improving public transport in New York City. For more click here.

Ken Livingston is releasing details of a new charge in London this week: Cars that emit more than 225 grams of carbon dioxide per kilometre will be charged £25. Those emitting up to 225g/km would be charged £8. Smaller cars, such as diesel hatchbacks and hybrid vehicles that emit 120 grams or less of carbon dioxide per kilometre, will be exempt.

Will Hong Kong join the world cities?