It states that drivers must stay in the right lane(s) unless they are passing:
“Any vehicle proceeding at less than the normal speed of traffic... must be driven in the right-hand lane available for traffic, or as close as practicable to the right-hand curb or edge of the roadway — unless overtaking another vehicle or preparing for a left turn.”
On a three lane road the left lane is the passing lane. The middle lane is not a passing lane. On roads four lanes and greater, the same applies - left lane is a passing lane, middle lanes are not. One is not permitted to 'camp' in the left lane.
What is 'normal speed'? It's the speed relative to the flow of traffic at the given time. Thus, if traffic is moving at 55 mph, and you are driving slower, the law requires you to stay out of the far left lane and/or to move over to the right.
As crazy as this might sound initially, if traffic is speeding in the left lane and you are doing the speed limit, you can't be ticketed for speeding but you can be ticketed for obstructing the flow of traffic in the left lane. The reasoning is that if you poke along relative to everyone else who is driving fast, you are a potential safety hazard. You can be charged with obstructing and/or impeding the flow of traffic. First time offense carries a fine of up to $150.00, a mandatory surcharge of $93.00, potential increase of insurance premium and 3 points on the violator's license at its a moving violation.
Are people ticketed for breaking this law? Not that I know of. But in NY we have a lot of 'crazies' on the road that get away with kinds of crap.