The executive doesn't stop there. He also foresees that private car ownership will "all-but end" in major US cities by 2025. Far fewer young Americans have driver's licenses than the previous generation, in part because ridesharing reduces the need for a personal car -- add self-driving cars to the mix and many urbanites may never need their own vehicle, Zimmer says. He even predicts that cities will change in response to the technology, such as reclaiming parking lots as community spaces.

The 2021 target may be difficult to hit. Numerous automakers only expect to start shipping their first self-driving cars that year, let alone put them into service in fleets. There's also the not-so-small matter of regulation. For Lyft to fulfill its dreams, many of the 36 states it operates in would have to legalize autonomy. Given that the country is only taking tentative steps toward legalization at the moment, there's no guarantee the needed legal framework will be in place. And assuming it is, will self-driving cars be sufficiently widespread that city dwellers could safely ditch their cars just 4 years later?

Whether or not Zimmer is realistic, his screed makes it clear where Lyft wants to go, and when. Much like Uber, it's convinced that the US' self-driving future is right around the corner. That's going to dictate not only its partnerships (such as with GM) and research, but its attitude toward drivers. They aren't completely going away in Lyft's vision, but they'll be less important than they are now.