Motorcycle officers (usually 2, sometimes 3, one time I saw 4) sit on their bikes on the south side of the street in any of several view-blocked apartment complex driveways and shoot radar and cars driving both east and west on Walnut. You cannot see them until you are right next to them, and they can see you for virtually the entire 1/2 block, both ways. I live in one of the apartment complexes and appreciate their presence, because the idiots in the cars think this stretch of Walnut is a freeway. Tustin PD is VERY professional and their radar units are ALWAYS calibrated. They WILL nail you for anything over 5 MPH over the posted limit.