Too many cars have created a lot of serious problems in our pletely replace the traditional ones.
Another solution is to develop modern public transportation systems and restrict the use of private cars. If the price of petrol rises constantly and the public vehicles are efficient and convenient enough, most people will not private cars. And the total number of cars in big cities will reduce greatly. On the whole, the elimination of air pollution needs the co-efforts from the government, the public and the environments. This problem will be solved only with the help of science and technology.