Waymo's chief technology officer and its chief operating officer will serve as co-CEOs.

What Happened: After spending almost more than five years at Alphabet Inc's (NASDAQ:GOOGL) (NASDAQ:GOOG) self-driving-car company Waymo, its chief executive John Krafcik has decided to step down. 

Krafcik will be replaced by two Waymo executives, Chief Technology Officer Dmitri Dolgov and Chief Operating Officer Tekedra Mawakana, who will head the firm as co-CEOs. However, Krafcik will stay on as an advisor. 

Before joining Waymo, Krafcik headed the Hyundai Motor North America unit as the CEO.

In a blog post on Friday, Krafcik said, "After five-and-a-half exhilarating years leading this team, I've decided to depart from my CEO role with Waymo and kick-off new adventures."

He said that he would be going on a sabbatical with his wife and relocating to Austin, Texas, from Silicon Valley.

Why It Matters: The change comes as Waymo is working on autonomous-driving technology for future ride-hailing and delivery services. 

Under Krafcik's leadership, the company launched a limited ride-hailing service in suburban Phoenix. Krafcik led Waymo's conversion into an independent subsidiary and raised $3.25 billion of external funding. 

In a recent blog post, Waymo announced that henceforth the company would address its mobility services as "fully autonomous driving technology" and ditch the term "self-driving."

While Waymo didn't name any automaker directly, it has contested the claims of Tesla Inc.'s (NASDAQ:TSLA) full self-driving being at par with Waymo's autonomous driving technology.  

Waymo was formed in 2009 as a project within Alphabet's Google unit. Its autonomous cars have driven 20 million miles on US roads.

Article updated to reflect correct number of miles driven in last sentence.