Registrar of Motor Traffic B Wijeratne says there about 1.9 million vehicles on the roads now though his department has registered about three million vehicles so far.
By the end of 2008, the vehicle population is expected to reach 2.4 million.
The country's three-wheeler taxis which use two stroke engines have become a key cause of atmospheric pollution in the city. Last year out of 300,000 vehicles registered in the island 64,000 were three wheelers.
Taking a cue from India the county has announced a ban on the import of two-stroke engine three wheelers and motorcycles. However the move is resisted by three wheeler owners who are politically powerful.
Unlike cars which use four-stroke internal combustion engines where only petrol or diesel is