Photo by Jeff Swensen/Getty Images(SACRAMENTO, Calif.) — The California Department of Motor Vehicles has revoked the registration of self-driving cars owned by Uber, and the ride-sharing company has removed the vehicles from the roads.

The DMV had taken the position that the vehicles were autonomous cars, and that the registrations had been improperly issued because they were not properly marked as test vehicles. The DMV did, at the same time, invite Uber to seek a permit to legally operate the vehicles within the state.

Twenty manufacturers are currently testing more than 130 autonomous vehicles on streets and roads in California.

In a letter to Uber, DMV Director Jean Shiomoto said that the agency “stands ready to work with you collaboratively,” and that a team of DMV employees would work to expedite Uber’s application to test autonomous vehicles.

The 16 vehicles being tested by Uber were self-piloted, but required a driver behind the wheel at all times as a precaution. Uber had argued that a person in the driver’s seat did not require a self-driving test permit.

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