Alphabet’s Waymo is now testing self-driving vehicles on public roads without anyone behind the wheel.

The company said members of the public will begin riding in its fleet of modified Fiat Chrysler Pacifica minivans outfitted with self-driving technology in the next few months. Passengers will initially be accompanied in the back seat by a Waymo employee, but will eventually travel alone in the robotic car.

The service will first be available to those who are already part of the company’s public trial already under way in Phoenix. Rides will be free to start with, but Waymo expects to begin charging for journeys at some point.

In announcement made on Tuesday at Web Summit in Lisbon, Portugal, John Krafcik, CEO of Waymo, the self-driving arm of Google’s parent company said, “Because we see so much potential in shared mobility, the first way people will get to experience Waymo’s fully self-driving technology will be as a driverless service.

“To have a vehicle on public roads without a person at the wheel, we’ve built some unique safety features into this minivan. Our system runs thousands of checks on itself every second. With these checks, our systems can instantly diagnose any problems and pull over or come to a safe stop if needed,” he added.

For now, there will be no charge for these rides. But the news is a step toward, with Waymo offering a paid service that competes with ride-sharing companies such as Uber and Lyft.

According to Gartner analyst Mike Ramsey, “This is a signal to the rest of the industry that Waymo has a business plan.

“The thought and energy they’ve put into putting something like this on the road is underestimated. Of all the companies out there, they’ve really thought holistically about this.”

The news signals Waymo’s confidence that its vehicles are safe enough to operate without a test driver. Waymo will have at least one employee in the back seat, but they will have no more control over the vehicle than any regular passenger.

The service also marks a major step forward in the development and roll-out of fully autonomous vehicles. While self-driving car companies have routinely tested their vehicles on public roads, they usually have a human sitting behind the wheel ready to take over should the autonomous technology fail.

Waymo has been testing the automated Chrysler Pacifica minivans without a human backup since 19 October in the Phoenix suburb of Chandler, Arizona, which has no restrictions on self-driving cars. The trials and new service have given Waymo the march on competitors Uber and other tech and automotive manufacturers such as Delphi, General Motors, Intel, Uber, Lyft, Apple and Tesla.

It is worth knowing that many self-driving companies have circled 2020 as the date when self-driving vehicle technology would be deployed on U.S. roads.

Recent Studies have also shown that most Americans do not want to ride in a self-driving vehicle due to safety concerns. Waymo recently released a safety report, offering some details on how it tests its vehicles. It also launched a campaign with partners this fall to educate the public about autonomous vehicles.

However, self-driving vehicle firms say the robot cars have the potential to be safer than human-driven vehicles because their is no risk of drowsiness, distraction or drunkenness.