Until now, Lyft drivers have had to set up a job in the Lyft app and then switch to a different one for navigation. The annoyance of having to do that will vary depending on the phone, but it's certainly not ideal. It's impossible to talk about the ride-hailing service without comparing it to its biggest rival, Uber, which has a proprietary in-app navigation system that's seen as a big advantage.
Lyft hasn't been ignoring the situation and has just announced that its own in-app navigation system is ready to go. Rather than go to the trouble of developing a solution, however, Lyft has partnered with Google to integrate its already full-featured technology.
Adding Google Maps navigation directly in the Lyft app should benefit drivers and passengers alike, as rides should get started just that little bit quicker. An update to the driver app will be rolling out shortly on Android, but it's only 'coming soon' for iOS devices. Presumably more Lyft drivers use Android phones, as you don't see that very often.