What app is this? Looks to be related to Google Navigation? My wife and I got ourselves a couple of Pixel XL phones last week.
I noticed an icon on her phone that wasn't in mine named 'Driving' and it looks like this. Opening the app takes me straight to Google Navigation - screenshot here.

 
icon and screenshot (click image for larger variant)

So what app is this? It looks to be a legit Google app but poking around in the Play Store didn't help much.
It's a Google Maps widget to go straight into the driving activity. You can see it when adding widgets to the home screen.