DETROIT (AP) — General Motors is expanding its Maven car-sharing service to Boston, Chicago and Washington, D.C.

The app-based service started in Ann Arbor, Michigan, in February and quickly moved to New York City.

The company says its answer to ZipCar already has started operating in Chicago, renting 30 vehicles at over 15 sites, for $8 per hour including gas and insurance.

In Washington the service will start at a luxury apartment complex next month and go citywide by the end of June. The service also is scheduled to begin operations in Boston this summer.

The expansion comes as GM, Ford and other automakers try to transform themselves from their traditional role as manufacturers and into mobility companies. Also this year GM announced a $500 million investment in ride-hailing company Lyft.