Robotaxi startup Argo AI said Tuesday it has begun operating its autonomous test vehicles without human safety drivers in two U.S. cities — Miami and Austin — a major milestone for the Ford• Volkswagen-backed company.

These driverless vehicles will not be transporting paying customers for the time being. However, they’ll be working in daylight and during business hours in dense urban locations, shutting down Argo AI employees that can summon the vehicles through a test application.

Bryan Salesky, CEO of the company, stated that they have been developing self-driving cars that are safe in urban areas since their inception in 2016.

“From day one, we set out to tackle the hardest miles to drive — in multiple cities — because that’s where the density of customer demand is, and where our autonomy platform is developing the intelligence required to scale it into a sustainable business,” Salesky said.

Argo tested its self-driving technology using modified Ford and Volkswagen cars with up to now human safety drivers.

Argo AI workers still make up the majority of robotaxis that carry Argo AI employees. Some vehicles were however, modified in December. available to passengers in Miami BeachLyft’s ridesharing platform.

Lyft holds a 2.5% share in Argo AI. Lyft vehicles will still have safety drivers, according to the company.

Argo AI is just one of many companies working to deploy robotaxis at scale in cities in the U.S. and elsewhere – none have yet reached the point of carrying paying passengers around the clock, in large volume, in busy urban neighborhoods.

General MotorsCruise, which is backed by Argo AI, started offering taxi driverless services in San Francisco. The service, however, can be limited to late night hours. isn’t yet charging for the rides. Waymo. AlphabetThe subsidiary was established out of Google Self-Driving Car, a pioneering project. It operates driverless taxis in Phoenix with passengers.