Drive to reduce pollution goes beyond cars

Singapore has controlled its vehicle population growth and usage rates since the 1960s, largely through high taxes and duties.

But it was not until 1990, when the vehicle quota system was introduced, that tangible results started to emerge. The system capped the vehicle growth rate - starting with 3 per cent a year and tightening to zero today - and buyers bid in a closed auction for the limited number of permits to own a vehicle.