By next year, drivers can choose to pay ERP charges with their ez-link card, or stick with their CashCard. And by 2010, CashCards will be accepted on buses and trains.

The Land Transport Authority (LTA) is likely to unveil a new electronic road pricing (ERP) in-vehicle unit (IU) in the second half of next year.

This new IU will be able to read both contact and contactless cards. This means people who use the bus and train, as well as drive, need carry only the ez-link card.

The contactless ez-link cards enable bus and train commuters to simply flash their card near a reader for an amount to be deducted.

Most CashCards in circulation today are contact cards, which means they have to be inserted into a reader. But new CashCards issued from July last year can perform contact and contactless transactions. There are more than 400,000 such cards out of a total 4.5 million CashCards in circulation.

Ms Jocelyn Ang, general manager at CashCard issuer Nets, said it will enter the public transport domain with the new card 'when the market is liberalised' in 2010.

However, drivers will be the first to enjoy the 'one card for all' when the new ERP IU is ready some time in the fourth quarter of next year.

"Having one card for several purposes is good," said call centre manager James Ang, 44, who drives and also uses public transport.

Another driver who takes the bus occasionally, Ms Kua Hwee Cheng, 38, said she is not quite ready to rely on one card for all applications.

"I tend to leave my CashCard in the car, because if if I take it out, I'll forget to insert it back," said the executive secretary. But she said the new IU's ability to accept both cards will be useful when the balance in her CashCard runs low.

The new ERP IU will have a 'self topping-up' function, possibly linked to a user's bank account.

When the card balance is low - say $5 - it will be topped up automatically the next time the vehicle passes an ERP gantry.

There are about six million ez-link cards in circulation. That number could be boosted with the new IU, which will be fitted to the 100,000 or so new vehicles that are registered here each year.

Yesterday, Nets unveiled a 'wave-and-go' carpark payment that uses its new CashCard - an alternative to the ERP-based drive-by system. Wave-and-go still requires drivers to wind down their windows to flash the card. But it is quicker than the old system where the CashCard has to be inserted into a reader. It is now available at Tiong Bahru Plaza and will be introduced at the National University of Singapore.

The use of electronic purses is expected to grow, with the introduction of a national standard. The Singapore Standard for Contactless e-Purse Application (Cepas) was launched last June.

Asked about a possible purchase of EZ-Link, the LTA unit that issues ez-link cards, Nets' Ms Ang said: "We've been in talks for a long time, but the ball is really in the Government's court."

The LTA has said it will divest EZ-Link eventually, but spokesman Naleeza Ebrahim said yesterday "we have yet to decide on when... and how to proceed with it".