S: (n) feeder line (a branching path off of a main transportation line (especially an airline))
S: (n) main line (the principal route of a transportation system)
S: (n) track, data track ((computer science) one of the circular magnetic paths on a magnetic disk that serve as a guide for writing and reading data)
S: (n) air lane, flight path, airway, skyway (a designated route followed by airplanes in flying from one airport to another)
S: (n) traffic pattern, approach pattern, pattern (the path that is prescribed for an airplane that is preparing to land at an airport) "the traffic patterns around O'Hare are very crowded"; "they stayed in the pattern until the fog lifted"
S: (n) flight path (the path of a rocket or projectile or aircraft through the air)
S: (n) beat, round (a regular route for a sentry or policeman) "in the old days a policeman walked a beat and knew all his people by name"
S: (n) bus route (the route regularly followed by a passenger bus)
S: (n) line of flight (the path along which a freely moving object travels through the air)
S: (n) orbit, celestial orbit (the (usually elliptical) path described by one celestial body in its revolution about another) "he plotted the orbit of the moon"
S: (n) beeline (the most direct route) "he made a beeline for the bathroom"
S: (n) circuit (an established itinerary of venues or events that a particular group of people travel to) "she's a familiar name on the club circuit"; "on the lecture circuit"; "the judge makes a circuit of the courts in his district"; "the international tennis circuit"
S: (n) Northwest Passage (a water route between the Atlantic Ocean and the Pacific Ocean along the northern coast of North America; Europeans since the 16th century had searched for a short route to the Far East before it was successfully traversed by Roald Amundsen (1903-1906))
S: (n) air lane, flight path, airway, skyway (a designated route followed by airplanes in flying from one airport to another)