Definition
Adapted Routes are pre-defined routes stored in the air traffic control computer system, used by controllers to issue clearances quickly and consistently between specific airport pairs or fixes. They are built from existing airways, jet routes, navigation aids, fixes, and sometimes radar vectors, and are coded into the host computer so the system can automatically generate or display them when needed. Adapted Routes may be flight-plan routes (Adapted Departure Routes, Preferred IFR Routes) or routes used internally by controllers for traffic management.
Plain English
These are ready-made routes already programmed into the air traffic control computer. Instead of building a route from scratch, controllers can pull up a standard one that's known to work between two points.
Context Anchor
Seen in the Pilot/Controller Glossary and in discussions of how air traffic control automation processes flight plans.
Derivation
"Adapted" here comes from the Latin adaptare, meaning to fit or adjust to a purpose. In this context, the routes have been fitted into the ATC computer system in advance — adjusted to suit the local traffic flow — so they're ready to use without being rebuilt each time.
Why Pilots Care
An adapted route can change a flight's distance, time, and fuel burn, so pilots must review and accept the new routing before departure or while en route.
Intuition Check
Adapted does not mean the pilot changed the route in flight. Here it means the route has been set up in ATC automation for flight plan handling.
Example Sentence 1
The controller issued a clearance using an Adapted Route between the two airports, so the routing came up immediately on her screen.
Example Sentence 2
Due to heavy traffic volume we were assigned an ADR instead of our filed airway.