SINGAPORE — More than 40,000 Grab passengers were overcharged due to its mobile application using outdated Electronic Road Pricing (ERP) rates, but the ride-sharing firm said that the error has since been fixed.

The Land Transport Authority (LTA) and the Public Transport Council (PTC) said on Friday (Dec 22) that they had received feedback on some Grab passengers who had been overcharged for trips.

LTA established that this was due to inaccurate ERP charges being applied to fares.

It directed Grab to go through its data to identify other trips where passengers might have been overcharged and to take corrective measures.

Grab found that the outdated ERP rates were applied to the final fares of 60,787 trips from Nov 20 to Dec 4.

"This error affected 40,431 passengers, with excess ERP charges generally ranging from S$1 (US$0.76) to S$3 collected for the large majority of affected passengers,"  LTA and PTC said.

"We understand from Grab that the ERP charges have been updated in its backend system and it has since taken action to reimburse all affected passengers."  

Last month, ERP rates were reduced by S$1 for a few gantries during the school holiday period.

The ride-sharing firm said in response to CNA's queries: "While Grab had earlier scheduled a revision to the ERP rates for these gantries, a temporary backend syncing issue prevented the automated ERP feature from populating the updated rates."

As a result, trips that passed through the affected gantries were overcharged. Grab said that this affected "a very small percentage" of rides between Nov 20 and Dec 4.

It added that the error has been fixed and it has notified affected customers and issued them a refund.

The automated ERP feature within Grab's driver app automatically populates the prevailing ERP rates based on the route taken during the trip. Grab drivers can also edit the ERP rates as needed.

Grab told CNA that the company has double-checked the ERP pricing for all gantries in its system to ensure accuracy, and "implemented additional internal testing on top of existing processes to prevent similar incidents from happening again".

"We sincerely apologise to consumers for the inconvenience caused," Grab said.

LTA and PTC said that they would investigate the incident. They added that operators of ride-hailing services are responsible for ensuring that accurate fares are charged to passengers. CNA