Highway strip

A highway strip, road runway or road base is a section of a highway, motorway or other form of public road that is specially built to act as a runway for (mostly) military aircraft and to serve as an auxiliary military air base. These runways allow military aircraft to continue operating even if their regular air bases, some of the most vulnerable targets in any war, are degraded or destroyed. The first highway strips were constructed near the end of World War II in Nazi Germany, where the well developed Reichsautobahn system allowed aircraft to use the motorways. During the Cold War highway strips were systematically built on both sides of the Iron Curtain, in many cases in response to the Six Day War and Operation Focus in 1967, where the Israeli Air Force in a surprise air strike disabled many of their opponents' air bases in just a few hours. Countries that have built highway strips include both West and East Germany, Singapore, North Korea, Taiwan, Sweden, Finland, Bulgaria, Switzerland, Poland, India, Pakistan and Czechoslovakia. The strips are usually straight sections of the highway, where any central reservation is made of crash barriers that can be removed quickly (in order to allow airplanes to use the whole width of the road), and other features of an airbase (taxiways, airport ramps) can be built. The road will need a thicker-than-normal surface and a solid concrete base. The specialized equipment of a typical airfield are stored somewhere nearby and only carried there when airfield operations start. The highway strips can be converted from motorways to airbases typically within 24 to 48 hours. The road would need to be swept to remove any debris before use by aircraft. Road runways can however also be quite small—the short runways built in the Swedish Bas 90 system are commonly only in length. The STOL-capability of the Viggen and Gripen allowed for such short runways. In the case of Finnish road airbases, the space needed for landing aircraft is reduced by means of a wire, similar to the CATOBAR system used on some aircraft carriers.