I'm not sure how I feel about that one. This summer was the first time I noticed this feature in Google maps, I was driving through BC on the way back to AK, on an unfamiliar route so had maps on. There were 3 or 4 times where the traffic ahead of me started abruptly braking hard. When I got to that point, maps chirped at me about police (which were not even running radar, just removing debris, helping someone, etc) so I can only guess they (the people ahead of me) had maps going in their vehicles too. It was a bit of an annoyance.