The latest example is GM executive Michael Ableson’s testimony Tuesday to a Senate committee, when he announced that GM will introduce self-driving cars for use by the Lyft ride-hailing service within a couple of years. A couple of years? Weren’t supposed experts telling us in 2014 that it would be more like a couple of decades before autonomous vehicles were road-ready? And I’m pretty sure that the unofficial target for introduction of a Google (GOOGL) autonomous car has been reported as 2020, and for an Apple (AAPL) car (even more unofficially) as 2019. As I was saying: This is GM?

We should remember that GM has been working quietly on vehicle autonomy for quite a while. In January it invested $500 million in Lyft and put an executive on the ride sharing company’s board. Last week it announced it was buying a 40-person software startup called Cruise Automation for a reported $1 billion; exactly what Cruise software does has not been disclosed, but GM apparently wants it badly and wants to keep it away from competitors. Barra has even said that she intends for GM to be first in introducing fully autonomous technology. That’s a squishy target, since autonomy is already arriving in increments, but it’s still an ambitious goal. Barra has also said she’s determined to make GM disrupt itself before outside disrupters do it. Lots of CEOs of big, old, incumbent companies say the same thing. Unlike most of them, she seems to be making a credible go of it.

I have no idea how well Barra will succeed. The auto industry is going through a historic transformation, and the stakes are as high as they can get. But I’m optimistic for two reasons. First, she understands that she won’t get anywhere unless she changes GM’s culture, a challenge that has defeated all of her predecessors of the past 30 years. She doesn’t talk about it much. “If we want to change this elusive culture, the way I look at it, it’s changing behaviors,” she told me 18 months ago, early in her tenure. Instead of talking about culture change, she focuses on everyone behaving differently every day, starting with herself.

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The second reason I’m optimistic is that Barra is entirely clear on what success means. “The ultimate proof point will be when we deliver exceptional financial results,” she told me. It’s not clear that investors are sold. The stock has jumped all over since she became CEO two years ago; right now it’s below where she started. A billion-dollar acquisition of a software startup might alarm some shareholders. That’s a lot of capital on which to earn a decent return. But the very thought of GM trying to be a leader in auto-related IT is one of those moves that makes me ask, This is GM?

For now, after the company’s decades of slow, then rapid, decline, and now its apparent comeback, things are probably going in the right direction so long as I’m asking that question.