The Truth about Interstate Highways and Emergency Aircraft Landings: Debunking the Myths

There is a common myth that stretches of interstate highways in the United States are specifically designed to accommodate emergency aircraft landings. This article delves into the facts behind this claim, addressing misconceptions and shedding light on the true purpose of these highways.

Design Considerations for Emergency Aircraft Landings

Some sections of the Interstate Highway System in the United States have indeed been designed with the capability to allow emergency aircraft landings. This is particularly relevant in areas near military bases or in remote regions where emergency landings may be necessary. The Federal Highway Administration (FHWA) has guidelines suggesting certain stretches of interstate highways be made straight and wide enough to facilitate such landings.

Examples from Libya

Not unique to the US, some road networks in countries like Libya also have specific sections designed for aircraft landing and taking off. These sections typically have the regular 8m wide tarmac carriageway that suddenly widens into an obvious concrete runway for a couple of kilometres. These sections are strategically placed, typically near military bases or in areas where such emergencies are more likely to occur.

The Eisenhower System and Its Multiple Purposes

The Interstate Highway System, often referred to as the Eisenhower Interstate System after its sponsor, Dwight D. Eisenhower, had diverse objectives. While the system was primarily intended to provide fast and efficient ground transportation for both personnel and war material, its adaptability for emergency aircraft landings was not among its initial considerations. The system was designed to support military and economic needs, and the urban myth around its aircraft-landing capability is not supported by its original design.

Debunking the Worksheet Act Myth

The Federal Aid Highway Act of 1956, which laid out the requirements for the interstate highway system, contains no explicit mention of aircraft runway requirements. Therefore, the idea that the act was intended to include such provisions is a falsehood.

Practical Considerations for Emergency Landings

While it is theoretically possible for an aircraft to land on a long stretch of a straight highway, the practicalities of such a scenario are challenging. Highway designs often feature intentional outward slopes to allow drainage to the median and culverts, making a smooth and safe landing surface difficult. Additionally, the presence of overpasses and underpasses makes it impractical to land and take off from these surfaces. Overpass heights were designed with the clearance needs of armored vehicles and tanks in mind, which do not necessarily apply to aircraft.

Conclusion

The myth of interstate highways being designed for emergency aircraft landings is an urban legend based on misunderstanding and misinterpretation. The enhanced straight sections of these highways do exist but primarily for the purpose of efficient transportation and not specifically for emergency landings. Understanding the original design objectives and practical limitations helps in debunking such myths and appreciating the true intentions behind highway engineering.