Chicago PD will post one car hidden in the cars parked alongside forest preserve drive and radio back to a large group of police cars witing to pull out from the apartment buildings or the churche just south of addison. They seem to be out 5-6 days a week and for 10 hours at a time. They write literally hundred of tickets in a day. The posted limit is 30 MPH on a wide 4 lane road with a cemetery along the length of one side of the road where cars are usually clocked. Cars going southwest are usually targeted, but occasionally you may catch an officer closer to Irving Park Road clocking cars going northeast from one of the side streets.