The hard work was done in Alteryx, using the R tool:
library(geosphere) orig <- read.Alteryx("#1") dest <- read.Alteryx("#2") inter <- gcIntermediate(orig, dest) write.Alteryx(inter, 1)
Feeding in two ordered lists of flight data from the OpenFLights routes then gave me a path of fifty points per route, which I could work with and “polish” in Alteryx before visualising in Tableau.
Here’s the result, the full dataset worked perfectly in Alteryx and Tableau but there were too many records for Tableau Public (1 million limit) so I had to cut it down. This just goes to show what an amazing combination Alteryx and Tableau are.