Route Weaver

The problem

An open route table that counts the wrong thing

The world’s airline network as it stood in June 2014 — 3,257 airports and 18,930 routes, each drawn as a great-circle arc — from a three-kilometer hop in Orkney to Dallas–Sydney at 13,808 kilometers, in 2D and on a 3D globe.

OpenFlights publishes the world’s airports, airlines and routes as open data. Reading it right is where the time goes: every route is listed once per airline and once per direction, the route table stopped updating in June 2014, and a straight line between two airports is the wrong path on a map.

What it covers

One source, three details, one map

• The source: the routes and airports come from OpenFlights, an open database of airports, airlines and routes, shared under the Open Database License — public use must credit OpenFlights, and a derived database stays under the same license. Its route table holds 67,663 rows, each one airline flying from one airport to another. Route Weaver ships one derived file with the app, under that license.
• Detail one, count airlines, not rows: every route is listed once per airline and once per direction, and codeshare partners add more rows. The app joins the 67,663 rows into 18,930 airport pairs and counts the distinct airlines on each pair — Atlanta to Chicago O’Hare has 20 airlines, the most in the table, where counting rows gives 39. 8,378 pairs have two or more airlines. About one percent of the rows, 730, use an airport code with no matching airport and are dropped.
• Detail two, the table ends in June 2014: the supplier of the route table stopped updating it in June 2014, so Berlin Tegel is on the map and Berlin Brandenburg, which opened in 2020, is not. The header and the footer label the routes as historical.
• Detail three, every route is a great circle: the shortest path between two airports follows the curve of the Earth. The app computes each arc itself, in 64 steps along the sphere, and the 137 routes that cross the 180th meridian are split so they draw across the Pacific — Sydney to Los Angeles is 12,061 kilometers and crosses that meridian near 15 degrees south.
• How it becomes a map: the map opens on the 600 routes listed by the most airlines; airport dots grow with the number of airports they connect to, and the 64 airports with 100 or more routes are gold; a strip lists the most connected airports, led by Amsterdam with 248; search by code, airport name or city, or click a dot; the panel gives the route count, the longest and shortest routes and the top ten destinations, each of which refocuses the map, with a back link; chips filter to two or more or three or more airlines; and the 3D globe lifts each arc 130 meters for every kilometer, capped at 2,200 kilometers, gold as it leaves the airport and blue as it arrives.

What it does not do

• Not today’s schedules — the route table is the June 2014 OpenFlights snapshot, and the app labels it historical.
• Not flight counts or passenger numbers — a route’s number is the count of distinct airlines that list the airport pair, codeshare partners included.
• Not an official product of OpenFlights — the data is theirs; the map and the app are All Things Spatial’s.

Where the data comes from

Every source in the episode

• OpenFlights airport, airline and route databases (ODbL) — openflights.org/data.php
• Esri dark gray basemap (2D and the 3D globe) — esri.com
• Source sheet with every endpoint — allthingsspatial.io/pages/sources.html

The airports and routes are OpenFlights data under the Open Database License, with the contents under the Database Contents License; the file the app derives from them is published with the app under the same license. The credit sits in the Route Weaver footer, with Esri for the basemap.