A man who was jailed for eight months for molestation in 2015 was back at it again, molesting two women last year within an hour of each other while giving them rides as part of a carpooling service.

Tan Keng Leng, 39, was working as a part-time GrabHitch driver when he touched the two women inappropriately after they were made to sit in the front seat.

The Singaporean was yesterday sentenced to a year and 10 months' jail after pleading guilty to three counts of molestation.

Two other charges for similar offences were considered during sentencing.

Tan picked up his first victim at around 5.30pm on Oct 12 last year. The 46-year-old woman tried to get to the back seat but found that the rear door was locked.

He told the woman to sit in the front passenger seat. As he was driving along the Pan-Island Expressway, she felt his left elbow touching the right side of her arm.

Deputy Public Prosecutor Goh Yi Ling said: "She thought this was accidental and shifted her body to the left. However, the accused again extended his left elbow towards her, and touched the right side of her right breast over her clothing.

"This happened at least four times during the entire journey."

The woman later alerted the police at around 8pm that day but, by then, Tan had struck again.

At around 6.15pm, he picked up a 24-year-old woman and molested her while driving along East Coast Road. He used his left elbow to brush against her right breast.

The DPP also told District Judge Hamidah Ibrahim: "When the car drove over a bump or a rough road surface, the accused touched the victim's right breast with his left fingers over her clothing. This happened at least three times during the entire journey."

DPP Goh, who urged the court to sentence Tan to two years' jail, said that he had "specifically targeted" his passengers by making them take the front passenger seat.

The women were unable to escape as they were travelling on the road within the confines of Tan's vehicle, the court heard.

Tan was offered bail of $5,000 and will have to surrender himself at the State Courts on Jan 16 next year to begin serving his sentence.

In a statement yesterday, Grab said Tan has been banned from the platform.

"We have zero tolerance for indecent behaviour and users found to display errant behaviour will be suspended from the platform. Our consumers' and delivery-partners' safety are important to us and we urge both passengers and driver-partners to treat each other with respect and kindness," said a spokesman.

For each count of molestation, offenders can be jailed for up to two years and fined or caned.