The Land Transport Authority (LTA) is reviewing rules that require taxis to ply the roads at peak periods and clock a minimum daily mileage.
The move is an attempt to level the playing field between taxis and newer ride-booking services such as Uber and Grab, which are not subject to such requirements.
The rules being re-evaluated are part of the taxi availability framework that was introduced three years ago.
According to LTA, these rules enable commuters to get a cab more easily but many in the taxi industry said they have led to cabs cruising the streets empty, and added to compliance costs for operators in enforcing the regulations.
This may change, LTA said.
In response to media queries, an LTA spokesman, in an e-mail reply yesterday, said: "LTA is reviewing our taxi regulations as commuter needs evolve, to progressively balance the playing field between taxis and private-hire cars. More details will be shared when available."
The taxi availability framework will remain in place for the remainder of this year, the spokesman added.
On Sunday, Prime Minister Lee Hsien Loong, in his National Day Rally speech, said the playing field for taxis and services such as Uber and Grab was "not quite level". He said the Government would "progressively sort all these things out".
Mr Lee added that the taxi industry is subject to some extra rules - for example, a minimum mileage and statutory requirements that make operating taxis more expensive. But he also noted that taxi drivers have the advantage of picking up fares on the street.
Uber and Grab drivers are booked using mobile phone apps.
Asked about LTA's review, National Taxi Association executive adviser Ang Hin Kee, speaking to The Straits Times yesterday, said taxi availability standards are "obsolete", as technology such as taxi apps is more effective in helping to match drivers to commuters.
"There are not many new relief drivers available and hence, it is tough for hirers to cover the minimum mileage and peak-hour availability on their own," he added.
Mr Ang said based on feedback from cabbies, there are fewer customers during the night, due largely to the competition from private car-hire services. This has made it harder for taxi hirers to find relief drivers willing to run the night shift.
Under the taxi availability framework, taxi operators are allowed to expand their fleet size, if their fleets consistently meet the requirements. If they consistently fall short, they can be fined.
The latest results, published on the LTA website, showed that in June, five cab firms - Comfort, CityCab, SMRT, Premier and Prime - failed to meet the minimum daily mileage requirement.
Only Trans-Cab made the mark.
Operators are expected to ensure that 85 per cent of the taxis in their fleet each clock at least 250km a day. On weekends, the requirement is 75 per cent of that.
ComfortDelGro, the largest operator with over 17,000 taxis under its Comfort and CityCab brands, said it had met the mileage requirement in the earlier months of this year.
"We thus qualify for a fleet increase for the first half of next year," said ComfortDelGro group corporate communications officer Tammy Tan.