A Chevrolet Bolt equipped with prototype self-driving sensors undergoes testing in San Francisco. Image source: Cruise Automation/General Motors.

General Motors' (GM -0.47%) latest acquisition isn't wasting any time getting to work. GM's newly acquired start-up, Cruise Automation, is already testing self-driving Chevrolets on the streets of San Francisco.

What we know about this test

Last week, The Verge published photos of two preproduction Chevrolet Bolt EVs. Each car had a self-driving sensor apparatus on its roof. One was wearing the "camouflage" that automakers typically apply to prototypes. The other Bolt, painted white, appeared to have Cruise co-founder Kyle Vogt in its driver's seat. California law currently requires that a self-driving test vehicle have a qualified (human) driver ready to take control if needed.  

GM had no comment on the report. But Cruise subsequently released its own photo of the white car (shown above) along with a one-sentence statement: "We are testing our autonomous technology on the all new Chevrolet Bolt EV in San Francisco."

While they look like the self-driving test cars we've seen from other automakers, Cruise's self-driving Bolts may be quite advanced. Earlier this month, an executive from ride-hailing service Lyft told The Wall Street Journal that GM and Lyft will begin testing a fleet of self-driving taxis on public roads in an unspecified U.S. city within a year. Lyft customers in that city will have the opportunity to opt into (or out of) the pilot program when they hail a Lyft driver with the company's mobile app.

Those self-driving taxis, the Lyft official said, will be Chevy Bolts. 

What it means for GM and the upcoming new Chevrolet Bolt

For one thing, it reinforces that GM has plans for its battery-electric Chevy Bolt that go far beyond simply throwing it out there to compete against Tesla Motors' (NASDAQ: TSLA) upcoming Model 3. Production versions of the Bolt won't start arriving at U.S. dealers until late this year, but already GM is aggressively pushing ahead with its development. 

That's not a surprise. Shortly after the production version of the Bolt was revealed in Detroit in January, GM officials stressed that the car had been designed from the ground up with ride-sharing and ride-hailing in mind. 

For instance: The Bolt's standard features include a low-voltage Bluetooth system that is always on, and that can recognize a digital "key" on a cellphone approaching the car -- for instance, a temporary digital key that the phone's owner might get via a ride-sharing app.

Another example: There are no footwells in the Bolt's back seat. The floor is completely flat right to the door. That's to make it easier for passengers to get in and out quickly -- for instance, when they're being dropped off by a Lyft driver next to a city sidewalk. The Bolt also comes with technologies intended to make it easy to drive in those kinds of situations, including a camera system integrated into the rearview mirror that gives the driver a much more complete view of the car's surroundings.

In the context of GM's $500 million investment in Lyft, and its own start-up car-sharing service Maven, those details made a lot of sense. Clearly, GM isn't just hoping to sell Bolts at retail; it's planning to put a lot of the little electric crossovers to work.

The Chevy Bolt is turning out to be lot more than a "me, too" electric car

In conversations with your humble Fool, GM officials at the Bolt's debut in January stressed that they the Bolt was designed as a "platform." That wasn't just a buzzword: They made it clear that the Bolt's onboard systems were designed with future technological upgrades in mind, much as Tesla has done with its Model S. 

It now seems clear that GM's purchase of Cruise for a reported $1 billion may have had a powerful motivator: It looks likely that Cruise was able to supply a "missing piece" or two that may have significantly accelerated the development of GM's self-driving system. 

If so, then the Chevrolet Bolt might quickly turn out to be an even more interesting product than we thought.