Cyclists on the road.
Waze for cyclists. They surelly don't want to use the screen to show the road or warnings, but their Waze could alert to other Waze users about there are cyclists on the road.
Actually, when I was doing more cycling on urban roads those warnings and notifications would have been handy. Warnings about road closures, objects on road, things like that aren't irrelevant. Plus cyclists can still contribute information to the Waze map by dropping in notifications about road construction when stuck in traffic, or road closures when stopped at a red light.
Would have been super useful in Minneapolis when they were redoing Nicollet Mall.