Traffic congestion is a prominent problem as the number of private cars is soaring by more than 1,000 each day in Beijing. In 2003, Beijing recorded about 2000 traffic jams. Traffic management officials com- Traffic congestion is a prominent problem as the number of private cars is soaring by more than 1,000 each day in Beijing. In 2003, Beijing recorded about 2000 traffic jams. Traffic management officials com-