@Carnage Bas 90 is a bit different from road bases, though. Bas 60 and Bas 90 are purpose-built airfields which may or may not include roads for some runways. Road bases can however also be built on their own, without any accompanying airfield to them. Just a long straight strip of road with some facilities for preparing airplanes hidden nearby.
Sweden's largest airport (by size) is a (former) Bas 90, which has a main runway and 3 small runways (the usual configuration) all purpose-built out in the middle of nowhere. I have also visited a Bas 90 where just the main runway was fully purpose-built with the 3 small runways being parts of the road running next to the base.
Bas 60 on the other hand is the older standard which just used the one runway (typically) and like half of them are civilian airports nowadays. Can be recognized by having a particular layout to them, as they were all built after the same blueprint.