Freight - connected to southern part of country by rail.
It's only connected to the southern part of the country by rail (and only took 126 years to built that). Exports from anywhere else in the country intending to be rail freighted to a departure by air in DRW have to travel a long long way to get there. There are no short cuts. Let's face it, DRW is a long way from the rest of the population, manufacturing, and agriculture.