Question: How long is the road course in the auto racing track that is across from a United States Air Force installation in Nevada?
Sentence (from "Stardust International Raceway"): Meanwhile, a replacement track, the Las Vegas Speedrome, was announced afterwards and opened in 1972, with a 1.8 mile drag strip and road course across from Nellis Air Force Base, which expanded into today's Las Vegas Motor Speedway.
Relevant evidence: Yes