Hi!
I have been thinking about this for quite some time. If we add data of road coverage and car ownership of different regions, it can have an effect on the load factor. This will make operating an airline out of small airports in rural areas much more viable, while it will make it a bit harder to operate in EU and US (because of the high infrastructure).
Why have both road length and car ownership? let's take an example: Taiwan has a car ownership of 297 cars per 1000 inhabitants. The road network compared to total area is 0,9 (total area in km2 ÷ total road length in km; the lower the number, the more covered the country is). Compared to a good covered country (Denmark, 0,6), Taiwan has an okay coverage. But compared to Denmark, Taiwan has a much lower car ownership, 297 compared to 549. So the roads in Taiwan are less congested than in Denmark, and more people are willing to take the plane, because they can't take the car, even if they have a good road coverage.*
If a country is too big to have a homogeneous number - e.g. USA or China - it is possible to have numbers for individual states/regions.
These numbers will have a big effect on short routes, but the effect will gradually get lower, the longer the route is; long haul won't get affected (who would like to drive 10000+ kilometres?). This means a Heathrow-Gatwick route will earn much less now than before, but a short route in Alaska will earn much more.
I might have forgotten something, but I'm sure I will remember some day soon
Questions about my theory are welcome this isn't at all final.
The CIA world factbook has the length of the road network of all countries; here it is listed:
http://en.wikipedia.org/wiki/List_of_countries_by_road_network_sizeThere is a list on Wikipedia with the car ownership with sources on most numbers:
http://en.wikipedia.org/wiki/List_of_countries_by_vehicles_per_capita*) This is a completely squared comparison, I haven't taken into account public transport and size of families (if one car per family, is it one car per 3 or 8 persons?) and general accessibility of the selected countries.
Another thing to consider when calculating the road length per area is the population density. Mongolia may have a bad road coverage, but it has a low population density too.
EDIT:
If you have 375 Euro to spare, Stephen, there is a worldwide compilation of road and traffic data from 2011
here. It contains all the needed information from the same reliable source.
