Hi,
I have been driving in DC area (in United States) and I find that Waze always gives me (camera, police, etc.) alerts about like half a mile away. However, in urban area this distance would often mean a few turns/crossings away and I would forget about the alert when I actually reach the camera/pothole, especially if after waiting a red light. Hence I suggest that Waze pop up alerts based on “travel time” (e.g. 15 seconds in advance) rather than on “travel distance” (the status quo).