Congestion Tax in Stockholm

One of the issues that were mentioned in the articles about IBM and innovation was congestion and how urban areas are having to tackle this problem despite the "world getting smaller" through connectivity.

I was just in Stockholm, Sweden where they after a trial in 2005-06 now have installed a permanent congestion tax. The trial was one of the first, which have now been copied by many other cities, and it essentially entailed setting up sophisticated tolls around all of the inner city of Stockholm. The toll varies depending on the day you enter and exit the city with rush hour having the highest charge. It uses technology to read the license plate and then cross-references them against the equivalent of the RMV to bill the owners (which is also automated) and in the permanent version, you don't even need a transponder to communicate with the system.

Despite a big debate and initial public opposition to the project, it's been deemed successful in alleviating congestion and some more details about how the technology works and the positive results can be found in these two articles:

Swedish Road Administration: Congestion Tax in Stockholm

IBM: How it Works