Originally Posted by alan s

Filtering is nothing more than sharing or splitting a lane with another vehicle. If it's legal for a car to pass you without moving over to an adjacent lane, by partially crossing the center line or simply moving over enough so as not to hit you, then they are sharing the lane with you. When you pass a car that is stopped at a light, you are sharing the lane with that car. In most jurisdictions there is no general prohibition on sharing lanes, so unless the law specifically prohibits lane sharing or lane splitting, then it is perfectly legal. Safety is another matter, and clearly overrides other considerations.