General Motors (GM 5.07%) said it has built 130 Chevrolet Bolt electric vehicles equipped with what it's calling its "next-generation" self-driving system, and it has begun testing them on public roads. 

In a milestone of sorts for the auto industry, these latest self-driving Bolts are the first autonomous vehicles ever to be built in a regular mass-production auto factory.

Workers install self-driving hardware on Chevrolet Bolt EVs.

In a step toward the mass-production of self-driving cars, GM's latest batch of 130 Chevrolet Bolt autonomous test vehicles was built at GM's Orion Assembly Plant. Image source: General Motors.

What GM said about its new self-driving test fleet

GM said it had begun building this current batch of self-driving Bolts in January, at its Orion Assembly Plant in Orion Township, Mich. At an event at the Orion factory on June 13, CEO Mary Barra said the completion of this batch of self-driving Bolts brings GM nearer to full mass production of autonomous vehicles: "This production milestone brings us one step closer to making our vision of personal mobility a reality. Expansion of our real-world test fleet will help ensure that our self-driving vehicles meet the same strict standards for safety and quality that we build into all of our vehicles."

Kyle Vogt is the CEO of Cruise Automation, the GM subsidiary charged with developing its autonomous-vehicle technology. He said these new vehicles will be tested in tougher urban conditions: "To achieve what we want from self-driving cars, we must deploy them at scale. By developing the next-generation self-driving platform in San Francisco and manufacturing these cars in Michigan, we are creating the safest and most consistent conditions to bring our cars to the most challenging urban roads that we can find."

The 130 new autonomous Bolts will join GM's self-driving test fleet, which has more than 50 Bolts with the prior-generation system already deployed in San Francisco; Scottsdale, Ariz.; and in and around Detroit. 

What it means for GM and for self-driving technology

Unlike many of its rivals, GM hasn't set a target date for the release of its self-driving technology to the public. That's deliberate: While GM may have an internal target date, executives have consistently said GM will begin selling self-driving vehicles only when GM feels the technology is thoroughly vetted and safe. 

A row of white Chevrolet Bolts awaiting their last parts.

These Chevrolet Bolt self-driving test vehicles are nearly complete and ready for deployment. Image source: General Motors.

GM's effort with Cruise Automation is thought to be fairly advanced, near the front of the pack in what is often characterized as a "race" to develop autonomous vehicles. But while GM seems to be aiming to be early to market (though not necessarily first), it has clearly put emphasis on creating a deeply integrated solution, one that's part of the architecture of the car rather than an add-on system from an outside supplier.

GM's approach could make for a more intuitive and more capable product, more like a Tesla (TSLA 2.08%) and less like a "regular" car with an optional self-driving system added. That could turn out to be a significant competitive advantage. But we'll have to wait to see the final product before we can judge.

What's next for GM and self-driving

GM owns 9% of the ride-hailing company Lyft, and both GM and Lyft have hinted at an upcoming large-scale test involving "thousands" of self-driving Bolts in Lyft service in several different cities. It's not clear when that will happen, but obviously GM will have to build those thousands of self-driving Bolts before it starts. 

It's very likely that the completion this batch of 130 test cars was a big step toward ramping up to larger-scale production of self-driving Bolts at the Orion factory. One clue: GM has said it will spend $600 million on autonomous-vehicle development in 2017.

Long story short: "What's next" on this particular path is probably a larger-scale production run of self-driving Chevy Bolts -- likely after the latest iterations accumulate some test miles.