how often do you see a officer next to the driver’s side of a stopped veh. with his back to traffic or butt sticking out in traffic."note” most people are left handed, therefore standing facing traffic next to the outside mirrow makes it hard for the stopped person to fire a weapon at the officer with his left hand (or right)plus it enables the officer to see into the vehicle via the windshield and the inside of the car. also the advantage of “facing” traffic enables the officer to watch for oncoming vehicles.