If while driving in the left lane, the car in front of you is preventing you from driving more quickly and is slightly behind the car in the lane to the right but without enough room to pass...pull up next to the driver on their right, giving them the impression that you are trying to cut in to pass. 90% of the time they will speed up to prevent you from cutting them off. Then you can switch back to the left lane and pass the car on the right.