The German city of Hamburg has announced plans to become car-free within the next two decades. It is an ambitious idea, but city officials obviously feel that the personal motorcar does not fulfill a function that walking, biking and taking public transport cannot. The goal of Hamburg's project is to replace roads with a green network, which will allow people to navigate through the city without the use of cars.     Banishing the car from urban areas is becoming a common trend in many European cities. London imposes a "congestion charge" on private vehicles entering the city centre during rush hours. Copenhagen is building bicycle superhighways radiating out from the city centre. These developments combined may make worrying reading for driving enthusiasts. Is the time of the personal car over?      In the century since the Ford Model T was introduced in 1908, global vehicle numbers have swollen to well over a billion. But according to recent research, the growth may have stopped.     According to Professor Michael Sivak, at the University of Michigan, "motorization" in the US might have reached a peak in 2008, and that the figures have been on the decline since.      "New York, Washington, Boston, Philadelphia, each have more than thirty percent of households without a light duty vehicle," says Sivak. In fact, the figures show that fifty-six percent of households in New York (which top the list) don't have a car. "I think that will be surprising to most people. It was surprising to me, and I am in the business. "       Sivak thinks a number of factors could be contributing to the trend, including workingfrom home and the movement of populations back to city centers. In China, Beijing and Shanghai are looking at plans to limit the number of new vehicles being registered to control prouth. It's a movement more cities are looking towards, particularly in the US. Why does Hamburg launch the "car-free" program?
To build a greener environment. To fix a worldwide road network. To call on people to take exercise. To replace the public transport.