There will be more frequent checks to nab unlicensed private cars as well as private hire cars plying illegally for fares.
Enforcement operations will be stepped up in areas with high traffic and where it has received much feedback, the Land Transport Authority (LTA) said yesterday.
Nineteen drivers have been issued with warnings by the LTA.
One driver was fined $15,000 and lost his driving licence for a year. His vehicle was forfeited. He was convicted in January for using his car to ferry passengers and driving without valid insurance.
Police reports had been lodged against him for charging fares of between $30 and $1,050.
Some areas where the LTA will be stepping up enforcement by plainclothes and uniformed officers are Clarke Quay, East Coast Seafood Centre, HarbourFront Centre, Marina Bay Cruise Centre Singapore, Resorts World Sentosa and the Singapore Zoo/Night Safari.
Drivers of private cars cannot be remunerated for carrying passengers, and those of private hire cars cannot tout, pick up customers in the street, or use taxi stands.
Offenders face a maximum penalty of a $3,000 fine and six months' imprisonment, and their vehicles may be seized.