PART›part of a road or track that is separated from the other parts, usually by a painted line: the inside/middle/outside lanethe fast/slow laneThey're widening the road from two to three lanes.
ROAD›a narrow road, usually in the countryside: We drove down a winding country lane.
BOATS/AIRCRAFT›a route that is regularly used by boats or aircraft: It's one of the world's busiest shipping lanes.