Have you ever noticed that billboards on American interstates usually seem to be off in the distance, in a raised clearing or high atop a hill, instead of closer to the road where it would be easier to read them? Thank Lady Bird Johnson.

Like most First Ladies, Mrs. Johnson had taken on a personal project to support – the beautification of the country. At first, she focused on prettying up the area around our nation’s capital, but as her project gained steam, flowers and tress were planted throughout Washington, D.C., dilapidated buildings were freshly painted, and playgrounds in the inner city were refurbished. While driving to her home state of Texas one day, she noticed that the many billboards along the freeways were eyesores, and felt that travelers would rather gaze at wildflowers while they motored. (Cynical Congressmen of that era snarkily observed that retailers deprived of billboard space would be forced to advertise on the string of radio stations Mrs. Johnson owned.)

Prior to the Highway Beautification Act of 1965, the federal government offered a financial incentive to any state that “controlled” the placement of billboards along Interstate highways to the tune of an extra one-half percent of road funding. Sadly, fewer than half the states participated in the program. The Outdoor Advertising Association fought the Beautification Act fiercely, and by the time it passed, the law had been seriously watered down. Billboards were permitted in “those areas of commercial and industrial use,” and billboard owners were compensated for any of their ads that had to be removed once the bill passed. The act has been amended many times since then.

For the most part, outdoor ads must be placed 660 feet of the nearest edge of the right-of-way, which is why some of us need binoculars to read them. (660 feet is a furlong, a measurement equal to one-eighth of a mile and still used to measure distances of thoroughbred horse races, providing the answer to the question that opens today’s fact.)