A highway strip or road runway is a section of a highway or motorway that is specially built to allow landing of (mostly) military aircraft and to serve as a military airbase. These were built to allow military aircraft to operate even if their airbases, the most vulnerable targets in any war, are 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. In the Cold War highway strips were systematically built on both sides of the Iron Curtain, mostly in the two Germanys, but also in North Korea, Taiwan, Sweden, Finland, Switzerland, Poland, Pakistan and Czechoslovakia.
The strips are usually 2 to 3.5 kilometres (1.2 to 2.2 mi) long 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 all debris before any aircraft movement could take place. 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.
Around the world
A number of countries around the world utilise the strategy of highways constructed to double as auxiliary airbases in the event of war.
In the Winter War of 1939-1940 the Finnish Air Force re-deployed its aircraft to makeshift airfields including frozen lakes to preserve them against Soviet air attack. The tactic was successful, with Soviet air raids on bases causing little damage and the vastly outnumbered Finnish aircraft scoring a high number of aerial victories.
As of 2017, all aircraft in the Finnish Air Force are capable of operating from road bases.
Currently Finland conducts drills on its road bases (maantietukikohta), around once a year. In the Baana 16 exercise in 2016 the Finnish Air Force flew F/A-18C and BAE Hawk, Pilatus PC-12 and C295M aircraft from a highway in Lusi. The Finnish Air Force uses arresting cables to quickly stop F/A-18s, which were originally designed to operate from aircraft carriers. The Swedish Air Force also took part in the 2015 and 2016 exercises, flying Gripen fighters.
Germany has a number of highway strips (NLP-Str - Notlandeplätze auf Straßen, emergency airfields on roads).
After the Turkish invasion of Cyprus, three highway strips were built in the Greek part of Cyprus, easily recognisable by a runway centre line and markings for the touchdown zone. They also all have aircraft turning areas at either end. One is located on the Limassol–Nicosia Highway (5,200 m or 17,100 ft) and one of the Limassol–Larnaca highway (5,000 m or 16,000 ft). The third is a much smaller strip located on the Limassol-Paphos Highway near to Paphos International Airport.
India has successfully tested its runway strip on a stretch of the Yamuna Expressway in Uttar Pradesh on 21 May 2015. It was built at a cost of ₹13,000 Cr for its combat jets of the IAF, a first for military aviation in the country. In June 2016, the Minister for Road Transport and Highways, Nitin Gadkari announced that the government was considering developing 'Road Runways' for commercial operations as well.
In Pakistan, The M-1 Motorway (Peshawar-Islamabad) and the M-2 Motorway (Islamabad-Lahore) each include two emergency runway sections of 2,700 m (9,000 ft) length each. The four emergency runway sections become operational by removing removable concrete medians using forklifts. The Pakistan Air Force (PAF) has used the M2 motorway as a runway on two occasions: for the first time in 2000 when it landed an F-7P fighter, a Super Mushak trainer and a C-130 and, again, in 2010. On the last occasion, the PAF used a runway section on the M2 motorway on 2 April 2010 to land, refuel and take-off two jet fighters, a Mirage III and an F-7P, during its Highmark 2010 exercise.
After an eight year gap, the seventh exercise, "Torrent 2016", was conducted near Tengah Air Base in November 2016. Signs, street lights and other fixtures were removed, and landing equipment installed temporarily, which included mobile arresting gear for the first time. F-15SG and F-16C/D fighters participated in the 2016 exercise.
Sweden started to build a few 1,500 m road strips (vägbas, literally meaning "road base"), from around 1949. The Six-Day War in 1967 (where the Egyptian Air Force was grounded by a quick surprise attack on air bases) inspired further development. The Viggen fighter/bomber was designed for shorter and narrower road strips which were built in fairly high numbers. 
Taiwan built a number of highway strips (戰備跑道 , lit. "war spare runway").
A large number of highway strips were built in the former USSR.(Аэродромный Участок Дороги, "airfield part of road").
Road runway section on Pakistan's M-1 Motorway with removable medians
Road runway section on Pakistan's M-2 Motorway with removable medians
C-130 Hercules aircraft on taxidrive on the autobahn A29 near city of Ahlhorn during NATO-exercise "Highway 84".
- Swiss Air Force, Uno Zero Zero – Ein Jahrhundert Schweizer Luftwaffe, Aeropublications, 2013, 324 pages (ISBN 978-3-9524239-0-5).
- "Puolustusvoimat" (in Finnish). Ilmavoimat.fi. Archived from the original on 25 June 2009. Retrieved 2015-12-17.
- Phillips, Graeme Highway doubles as flying doctor landing strip July 23, 2015 Government News Retrieved February 21, 2017
- RFDS Emergency Landing Strip, Eyre Highway, between Mundrabilla and Madura Pass, Western Australia Retrieved February 21, 2017
- Engle, Eloise/ Paananen, Lauri (1973) The Winter War Sidgewick&Jackson ISBN 0 283 97949 6 p60
- Bitzinger, Richard A The Finnish Air Force Faces the 1990s July 1989 p4
- Finnish Hornets on the road Combat Aircraft Volume 18 Number 1 January 2017 pp70-75
- Lock, Alex Watch the military drill where Finland launches F-18s off of a highway October 4, 2016 Business Insider Retrieved February 21, 2017
- "Abandoned and Little-known Airfields: Cyprus, District Larnaca".
- "Abandoned and Little-known Airfields: Cyprus, District Paphos".
- "Indian Air Force(IAF) Mirage -2000 Lands at Yamuna Expressway". Press Information Bureau. 2015-05-21. Retrieved 2016-06-25.
- Kumar, Deepak (21 June 2016). "Turning roads into runways may be a stretch and here is why". Moneycontrol.com. Retrieved Jun 25, 2016.
- Combat Aircraft (European Edition) (magazine), September 2003, pages 76-79
- Factsheet: RSAF Exercise Torrent 2016 November 13, 2016 Ministry of Defense Retrieved February 24, 2017
- 'Exercise Torrent 2016' Combat Aircraft Volume 18 Number 1 January 2017 p18
- Advisory on RSAF Exercise Torrent 2016 November 3, 2016 Ministry of Defense Retrieved February 24, 2017
- RSAF to conduct alternate runway exercise at Lim Chu Kang Road from Nov 10 to 14 November 3, 2016 The Straits Times Retrieved February 23, 2017
- Fighter jets, including new F-15SG planes, take off from Lim Chu Kang Road in RSAF's Exercise Torrent November 13, 2016 The Straits Times Retrieved February 23, 2017
- "Military Aviation in Sweden". http://www.avrosys.nu. External link in
|work=(help)[full citation needed]
Media related to Highway strips at Wikimedia Commons