Excerpt from the Washington State Drivers Test
Left Lane Refresher (Circle any that apply)
The left lane is for:
A. Cruising. Whatever speed I choose is the speed at which everyone behind me wants to travel.
B. Just another lane. Whatever speed I choose is the speed at which everyone behind me wants to travel.
C. A safe, slow lane. To get away from someone who realizes I'm an incompetent driver and wants to pass me. Passing on the right is much more acceptable, so I can move to the left lane, and then slow down. D. Going exacctly 60MPH. No driver should go more than 55, really, but there are times to go really fast and speed up to 60, which is the legal driving speed between Seattle and Olympia. It really should be slower, though. I can't imagine that others may want to get anywhere in an adequate amount of time.
E. To make sure other people in the left lane are going the speed limit. Merging in the left lane allows me to control over drivers already in the left lane, causing them to slow down or have to brake suddenly, and possibly cause an accident; but it's my duty to ensure that the Washington highways are always full to bursting with slow and/or stopped traffic.
In case of Rain*
A. Brake suddenly and often. Otherwise, traveling at a constant rate of speed in the rain may cause calm and safe traffic flow.
B. Pole Position.
C. Alternate slowing down and then speeding up in an erratic fashion.
*Rain is unlikely here in the state of Washington. However, in the event that a water-like substance does fall from the sky, you should be prepared. Be sure and brush up on those left lane skills!