GrabHitch enables private car drivers to offer a ride to passengers heading in the same direction for a fee.
GrabShare, the carpooling service offered by Grab's commercial drivers, has been suspended during the same overnight hours since June.
The company's other ride-hailing services are still available during those hours.
"Grab has always taken a proactive approach to ensure that our driver-partners and passengers will have a safe and positive driving/riding experience," the company said on Wednesday.
Ride-hailing firms in Asia have faced questions about safety after incidents involving drivers and passengers this year.
China's biggest ride hailing firm, Didi Chuxing, implemented safety measures after a public outcry over the murder of a 20-year-old passenger by her Didi driver in August, the second such incident since May.
