The circular runway idea made me think of an idea that has been going around for a while:
Aerotropolis.
This is the cool idea that a city should be laid out and planned around its airport. I suppose it is great for new cities that will be built in the Middle East or in the Great Plains of the United States, but the big question is what happens when the city grows and the airport becomes too small for the sprawling metropolis out with its boundaries?
