A Google spokesperson explains:
Promoted pins in navigation are not new – they let people see relevant ads for businesses like gas stations, restaurants, and stores along their route. To avoid driver distraction, these ads do not pop up, expand only if they’re tapped on, and disappear quickly after a short time.
This. I live in a busy city. I know several routes through and around it. I need the traffic data. I need it to tell me there is a wreck.
I don’t need to know (usually) how to get there.