premise: Then , once I get on the main road to the lake , a Police car flies by me , and then stops and cuts off the road right in front of me , and motions me to turn around . So , I turn around and go back to the highway . I open up google maps and try to find a different road to get to the lake . What 's a possible reason the police car motioned the writer to turn around ?
hypothesis: Because the police car flew by them .