QUICK quiz: Are there more off-peak cars or taxis on the road here? Pat yourself on the back if you said off-peak cars.

There are now about 34,000 off-peak cars here, compared with 24,400 cabs.

The story was quite different just a few years ago. In 2003, there were only 2,644 off-peak cars here - and 19,384 taxis.

Wearing red number plates, off-peak cars attract $17,000 less in taxes than normal cars. But they can be driven only between 7pm and 7am on weekdays, after 3pm on Saturdays and all day on Sundays and public holidays.

If owners want to use them outside the prescribed hours, they have to buy a $20 'day licence'.

The main reason for the explosive growth of off-peak cars lies in falling car prices.

Today, a Toyota Corolla costs around $60,000. A $17,000 rebate works out to savings of nearly 30 per cent. But when the Corolla was $75,000 in 2003, the saving worked out to be only 22 per cent.

Car prices have halved from their peak in the mid-1990s (when a Corolla cost $130,000). Hence the growing popularity of off-peak cars.

Last year, the population rose by 39.2 per cent to 33,983, although new unit sales fell by 10.4 per cent to 11,180.

In tandem, off-peak car violations rose to 1,067 cases, from 894 in 2006 and 761 in 2005.

But with COE premiums set to rebound with an anticipated supply shrinkage this year, car prices could well head north again. And when car prices go up, off-peak car sales usually go down.