For those of you who aren't familiar with Waze:
it uses user information, both passive and active updates, to inform other users about current traffic load, accidents, road hazards, speed traps and other things.
In places where there are many Waze users , you get valuable current information that help you save time. Israel, where Waze was/is developed, is one such place. Probably more than 25% of the Israeli drivers are using it.
Google purchased Waze in 2014, especially for the user data.
Nowadays Google maps real-time updates take advantage of part of the data made available by Waze.