From the FAA Historical Chronology, 1926-1996...
”Oct 1, 1969: Sixteen area navigation routes opened between 11 U.S. cities on an interim basis pending formal rulemaking. The new routes were the first in a projected nationwide area navigation route system designed to increase airway capacity.
They ran between the following cities:
Chicago and New York (two routes);
Los Angeles and Chicago (two);
Kansas City and Minneapolis (two);
San Francisco and Chicago (two);
Atlanta and Pinehurst, N.C. (two);
Knoxville and Atlanta (two);
Houston and Dallas (four).
In succeeding months, additional cities were linked as more routes were developed (see Apr 29, 1971).
The primary air navigation system in use in the United States in 1969 required pilots to fly directly toward or away from the ground-based radio navigation aid (a VOR or VORTAC) transmitting a line of position, or radial. With area navigation, aircraft did not have to fly a track to or from a navaid, though they did depend on signals from VORs or VORTACs. Pilots flying appropriately equipped aircraft could, within the limitations of the system, follow any preselected arbitrary track. An airborne computer calculated the aircraft's position and displayed track and distance to a point selected by the pilot or prescribed by the controller. The system's advantages included: routes could be established along the shortest and most convenient paths; parallel and one-way routes could be established to reduce congestion; aircraft could be segregated according to speed and destination; navaids could be placed at accessible points on more favorable terrain; departure routes could be designed to lead directly from the runway to the appropriate parallel airway; and arrival routes could be designed to accept traffic directly from en route airways. (See Mar 6, 1972.) “
Just curious -- does any of this sound familiar ? “... designed to increase airway capacity...“ “...routes could be established to reduce congestion... “
I hired on in 1981. I never saw any “area navigation routes” until they put a GPS airway through CLT Approach’s airspace around 2000 or so.
I can just see the edited version of the FAA’s history:
"The primary air navigation system in use in the United States
October 1, 2008