Only 900 out of an estimated 20,000 to 30,000 private-hire cars here have had mandatory stickers pasted on them.
At the same time, 24,000 people have applied for the Private Hire Car Driver's Vocational Licence (PDVL), which all current private-hire drivers must apply for by the end of next month.
The Land Transport Authority (LTA) revealed the numbers yesterday following queries from The Straits Times. A spokesman for the National Private Hire Vehicles Association said the low take-up for the stickers could be because the deadline was still more than a month away.
But he acknowledged that many drivers who currently offer private-hire services would stop because of the sticker rule. "There will always be people who moonlight," he said. "These people might stop driving because their companies might not allow them to moonlight."
Part-time Grab driver Ng Chun Kong, 33, said he has yet to get the stickers - to be pasted on both front and rear windscreens - and will do so "some time next week".
"I don't know how people will feel when they see the sticker on my car," the business development manager said. "I know of some drivers who will be giving up (driving) because they feel their employers may have an issue with them driving."
Mr Ng said he has applied for the PDVL.
The LTA said of the 24,000 people who have applied, 6,000 have completed the relevant checks, and it has given approval for them to register for the PDVL course.
"Applicants whose applications reach LTA before June 30, 2017, have up to one year to attend and pass the PDVL course," an LTA spokesman said, adding that only 400 of those who passed screenings have registered for the course.
Mr Neo Nam Heng, chairman of diversified Prime group, said the new rules and regulations may discourage many current drivers to drop out.
He said: "Actually, 24,000 is not that big a number. There have been reports that there are as many as 50,000 private-hire drivers here."
Mr Neo said he will collect stickers for his fleet of more than 500 private-hire vehicles next week.
Commuter Ashley Wu, 37, said it is a good idea for private-hire drivers to undergo training.
"Many of the drivers are young and inexperienced," she said. "They know only how to follow the GPS. And they're not as professional as taxi drivers. So it's good that they go for a course."