I would like to salt flats some where to test land speed record cars on because on the runway you can speed up (for some not to full speed) but you cannot slow down that brings me to my next point breaking parachutes to slow down cars and planes quickly also the salt flats need to be as flat as the runways because otherwise the car just bounces into the sky and breaks apart or falls back down and crashes and the flats need to be really long like the size of Maywar or something and finally arresting wires and arresting hooks so you can land on aircraft carriers easier