With 130 new prototypes and dozens of first-generation cars on the road, GM now has a fleet of more than 180 self-driving EVs deployed in three cities.

General Motors has finished building its second fleet of autonomous Chevrolet Bolt prototypes.

The latest round includes 130 EVs outfitted with the company's "next generation" of self-driving hardware including new LIDAR sensors, cameras and other upgraded equipment.

The new vehicles join more than 50 Bolt prototypes outfitted with first-generation autonomous technology. The company has not disclosed specific details of the hardware differences between the older and newer models, however the latest announcement hints at progress toward full production.

"To achieve what we want from self-driving cars, we must deploy them at scale," says Kyle Vogt, chief executive of Cruise Automation, a San Francisco-based startup now owned by GM.

The cars are currently deployed in San Francisco; Scottsdale, Arizona; and metro Detroit.