The city’s vehicle population crossed the 46 lakh-mark this week, taking the density to 2,300 vehicles for every km of road and leading to a ‘population explosion’. There is no cap on the number of cars that can be registered, which could be disastrous in the near future. The government should make purchase of new vehicles difficult so that people buy and sell only “used cars” to ensure that the number of vehicles remain constant and excess vehicles get phased out. The biggest problem is that on a day when even 40 percent Mumbaikars take out their vehicles, the entire city will be blocked in one hour. Many people also get the vehicles from other cities or states without registering it, which adds to congestion.