[metmom]

Interstates, IIRC, are designed so that every fifth mile is a straight line without any curves, so that a plane could land on the highway in an emergency—or if air bases/airports were all nuked in a future atomic holocaust.

I never knew that. That's a fascinating piece of trivia.

[Berlin_Freeper]

How come automobiles don’t have a sky mirror?

[deport]

One Mile in Five: Debunking The Myth
by Richard F. Weingroff
Editor’s Note: In the following article, we let the Federal Highway Administration’s “unofficial historian” get something off his chest. He needed to vent.

I don’t know if 10 percent of the Russian government’s income comes from the sale of vodka. I don’t know if a cow can go upstairs, but not downstairs. And I certainly don’t know if a duck’s quack doesn’t echo.

But I do know the following statement is false: The Eisenhower Interstate Highway System requires that one mile in every five must be straight. These straight sections are usable as airstrips in times of war or other emergencies.

False though it is, this “fact” has become a fixture of Internet Web sites with names such as “You Probably Didn’t Know That ...” and “Weird Fact Heaven.”

https://highways.dot.gov/public-roads/mayjune-2000/one-mile-five-debunking-myth