I have always wondered how much it would cost to build a 10 mile stretch of concrete track say 14 feet wide? Anybody in the road building business.
I just pulled these numbers from a 2012 study of highway costs in Arkansas (I only used it because it was the first comprehensive highway-cost study to pop up). Assuming that it would probably be necessary for safety reasons to have, say, at least a 40-foot-wide track, you might look at a four-lane highway with a painted median (with each lane about 11 feet wide) for your model. In Arkansas, building this kind of highway in a rural setting would cost approximately $4,725,000 per mile (I'm not sure if that includes the land or not, but I'm assuming not). Now, a remote desert track might be cheaper than that, but using those numbers, a 10-mile, 44-foot wide track would cost about $50 million, PLUS (I would assume) another $25 million (or maybe less, who knows) for a parallel return road. Then, of course, you would have the extra costs of building parking and pit areas, staging and shutdown areas, and possibly access roads, which would probably take the whole thing up to $100 million.
Believe me, I've often thought how awesome it would be for someone or some entity to build such a facility, but the above costs seem depressingly realistic to me (and no, I don't work in the road-building business)...
Gary