Some motorists here think they have found a way to avoid paying for parking by fooling the hands-free Electronic Payment System (EPS).

And all it takes is a particular type of card inserted into a car???s in-vehicle unit (IU) along with the CashCard.

This small number of drivers could be committing a criminal offence.

Carpark operators told The Sunday Times that they are aware of the problem and are working to find a solution.

But chasing evaders or upgrading their systems would cost them far more time and money than they are losing, they said.

Ten motorists contacted by The Sunday Times said they know of at least five carparks around the island where they can avoid paying.

Last Friday, The Sunday Times got the permission of a carpark operator to test the cheaters??? technique.

The car entered the carpark as normal. An antenna at the entrance communicated with the vehicle???s IU, the system recorded the entry time and the barrier went up automatically.

Before exiting the carpark, The Sunday Times inserted one of these cards into the IU. Sure enough, at the exit gantry, another antenna recorded the time, the barrier was raised and the car was free to drive away ??? but no money had been deducted from the CashCard.

A repeat test yielded the same results.

One 26-year-old driver told The Sunday Times he has been exploiting the loophole for the past two years and does not feel guilty for cheating.

???I figure I will never get caught,??? said the man, who declined to be named. ???If the carpark owners do not update their systems, it???s their fault.???

He reckons that since he was tipped off about the technique by a friend, he saves about $30 a month.

???Impossible!??? was the response from engineers at Mitsubishi Heavy Industries (MHI), the developer and sole distributor of the EPS, when told about the flaw.

???The barrier will never open until money is deducted from the CashCard,??? said Mr Takayasu Obata, general manager of MHI???s South-east Asian subsidiary.

But as the Sunday Times test proved, it can be done.

Mr Obata admitted that the system has a 0.1 per cent error rate and said the loophole may be a result of the individual operators??? software.

???Ultimately, how secure the EPS is depends on how the system integrators write the software for their machines,??? he said.

System integrators tailor the EPS software to the needs of carpark operators or the building???s management.

Local system integrators here know about IU tampering, but say they have yet to receive complaints.

While most say they are looking into the matter and are trying to improve on their systems, they added that there is no ???100 per cent, foolproof EPS???.

Said a major player in the carpark technology industry, who provides and customises the EPS for 90 carparks in Singapore: ???Humans will always be smarter than machines, so they will always find ways to outsmart technology.???

The paragraph should read: It is unclear how much carpark operators may be losing to cheats, but according to one report last month, CapitaCommercial Trust has lost $150,000 in unpaid fees in seven carparks last year.

Even if that is the case, it still does not seem to be enough to force operators to take action.

Said carpark operator P-Parking???s general manager Johnson Tan: ???Even if we want to track these vehicles, it will be a lot of trouble and a waste of time and money.???

Lawyer Han Wah Teng said it is ???not feasible??? to catch the culprits.

???The amount is too small for carpark owners to mount claims on individual users,??? he said.

Mr Han said operators should upgrade their systems, but this is a costly move that can set carpark operators back by about $300,000.

Mr Tan said: ???It???s too expensive. I will be spending more than the amount I am losing.???

How they do it

The fee cheats enter the carpark normally, with a CashCard in the car???s IU.

The carpark???s Electronic Payment System records the entry time, and the barrier goes up automatically.

But before exiting the carpark, they slip a particular type of card into the IU along with their CashCard.

At the exit gantry, the system once again records the time and raises the barrier.

But the extra card somehow prevents money from being deducted from the CashCard.