nuTonomy, a developer of state-of-the-art software for self-driving cars, and Grab, Southeast Asia’s leading ride-hailing app, announced on Friday a partnership to expand nuTonomy’s ongoing public trial of self-driving cars in Singapore, which Grab described as “the first such public trial anywhere in the world.”

The trial will give select Grab users a chance to experience the full end-to-end experience of e-hailing and riding in a nuTonomy self-driving vehicle (SDV).

The combination of nuTonomy’s SDV software and technology system with Grab’s fleet routing technology and mapping in its app will enable both companies to study the end-to-end user experience of on-demand hailing of SDVs, said Grab.

Select Grab customers can use the Grab app to book a ride in a nuTonomy SDV through a special “robo-car” fleet icon, according to Grab.

The company said all rides are free-of-charge and customers may travel within the one-north business district as well as to adjacent neighbourhoods.

A nuTonomy safety driver and support engineer will ride in each nuTonomy SDV to observe system performance and ensure passenger comfort and safety. If a trip requires travel on roads outside of one-north, the safety driver will take control of the vehicle for that portion of the trip.

The public trial will run for the next two months, and may be extended by the companies for as long as it continues to yield valuable feedback and data, Grab said.

NuTonomy, a 50-person startup out of MIT, in August became the first company in the world to do public testing of robot taxis, and the partnership expands its public trial of its self-driving car service in one-north, where the company has been conducting daily testing of its self-driving cars since April.

Last week, the U.S. outlined its rules of the road for autonomous cars in a long-awaited document from the National Highway Traffic Safety Administration that includes a 15-point checklist for safe design, development, testing and use.