Ever wondered why the airstrips are always straight? Or, why they are designed a certain way. Ever since aircraft were used in warfare, to commercialization, these airstrips have remained the same. But, something new is coming and prototypes are already in development. The aircraft endless runway is the future solution to space and the effective use of time. This will make it possible for an aircraft to stay operational all the time, both during take-off and during landing with the headwind.
Will these models ever see the light of the day? The technology seems good on paper but their applications might be very limited. A lot of speculations have been brought on this matter. For example, having straight runways helps the pilot use the complete thrust to lift off while making curves is near impossible. A straight path helps it accelerate much faster and take off easily. But, is it all? What are the benefits of these circular endless runways over the traditional ones?
BBC Interview Sheds Light
In a recent interview on the BBC, the scientists explained the theory behind this. Aircraft can take-off and land at any point on the circle. And make certain that there are no crosswinds, but only headwinds. According to scientists the straight runways give a feeling of a roller-coaster take-off that can be jerky and unpleasant. In this case, the passengers will experience a similar feeling when the plane makes a curve mid-air high in the sky. And, because of the centrifugal force, the aircraft will move slowly and smoothly.
What has been done extensively is to test the model in simulations, but the idea has been able to attract a lot of debate and gossip over the internet. 
There is a Reddit Thread that talks on benefit and discuss in-depth this idea. But, at the same time, some people are citing real concerns such as traction, visibility issues with circular curves, and shifting winds because of constantly changing direction. These are very fundamental issues which are both sensible and appreciable to be answered by the pro-endless advocates.
History
It might be astounding to find out that the idea itself has been around since the end of World War 1 in 1919. Back in those days, popular science proposed building a circular runway that can be mounted on towers of rooftops and in the high-rise building where transport can be substantially made easier and free for the road dwellers. This was the idea of take-off and land residents without having to crowd the roads.
According to Henk Hesselink, this would be a much safer way to travel. He is a researcher at Aerospace Center in the Netherland and the idea that it can handle over four times the traffic of a traditional runway making it more efficient and sensible. He argues that at time 3 aircraft can take-off and land and, of course, about saving valuable real-estate in return. The terminals are in the center of these 3.5mile diameter aircraft endless runways.