In which lane should you generally drive on a multilane highway?

LANE DISCIPLINE on multilane highways is both a legal requirement and a safety practice in most US states. THE RULE: KEEP RIGHT EXCEPT TO PASS. Drive in the rightmost lane appropriate for your speed and exit. The left lane is for passing slower traffic and should not be used as a default travel lane. WHY THIS RULE EXISTS: (1) Traffic flow efficiency: vehicles needing to pass don't have to maneuver around slow left-lane drivers; (2) Safety: left-lane camping (driving slowly in the left lane) forces faster vehicles to pass on the right, which is statistically more dangerous; (3) Emergency vehicle access: emergency vehicles use the left shoulder and need clear access; (4) Reduces rear-end pressure: when slower drivers block the left lane, faster vehicles following closely create a tailgating hazard. LEGAL STATUS: Over 40 states have laws specifically requiring drivers to keep right except to pass; violation can result in a ticket even if you are traveling at the speed limit; in some states, left-lane driving is a primary offense (can pull you over for this alone). EXCEPTIONS: When preparing for a left exit or left turn; when traffic density makes lane changes impractical; when road conditions or congestion make it safer to remain in the left lane temporarily. SPEED LIMIT DOES NOT OVERRIDE: Even if you are traveling at the speed limit in the left lane, you should move right if others want to pass — in a keep-right state, the obligation to move right exists regardless of your speed.