What do police officers look for when searching for drunk drivers on the highways?

The following is a list of symptoms in descending order of probability that the person observed is driving while intoxicated. The list is based upon research conducted by the National Highway Traffic Administration:

  1. Turning with a wide radius
  2. Straddling center of lane marker
  3. Appearing to be "drunk"
  4. Almost striking object or vehicle
  5. Weaving
  6. Driving on other than designated highway
  7. Swerving
  8. Speed more than 10 mph below limit
  9. Stopping without cause in traffic lane
  10. Following too closely
  11. Drifting
  12. Tires on center or lane marker
  13. Braking erratically
  14. Driving into opposing or crossing traffic
  15. Signaling inconsistent with driving actions
  16. Slow response to traffic signals
  17. Stopping inappropriately (other than in lane)
  18. Turning abruptly or illegally
  19. Accelerating or decelerating rapidly
  20. Headlights off