A phrase often used to describe routes along which space craft travel in (usually "golden age") science fiction. The space lanes are part of science fiction mythology. They are part of the inaccurate Sea/Space simile that is often used in science fiction - similar to the concept of the Space Navy.
“Good. We haven’t sighted any ships?”
“No, no! We’re way of the regular space lanes.”
Not Final!, Isaac Asimov, 1941.
The space lanes are the celestial equivalent of the ocean’s trade routes and shipping lanes (also known as “sea lanes”, hence “space lanes”). The path of a trade route is determined by the meteorological and geographical features of the region that must be traversed - currents, storms, rocks, sandbars, etc. A space lane’s path is defined by asteroid belts, solar storms, interstellar dust clouds, etc.
But here’s the thing: Space lanes are fiction, not science. In The Sands of Mars (Arthur C. Clarke, 1951) the main character Martin Gibson, a science fiction author, laments that much of his early science fiction was wrong because space ships turned out nothing like the ships of the sea, and their crews nothing like sea dog sailors. Later he notes that there are no space lanes because the planets are constantly in motion in their orbits and thus relative to each other. This means that the region of space traversed each time one travels from Planet-A to Planet-B is different. Courses are calculated on a mission-by-mission basis so there are no set space lanes written in a big “Space Almanac”.
A concept similar to that of a space lane: The interplanetary superhighway. See the node for more.