I was recently asked why drag races are a quarter mile long. Since I used to help my dad with surveying when I was a kid (a job my dad affectionately called "holding the dumb end of the chain") I actually knew the answer and thought I'd write it down in case anyone else is interested in trivial stuff like that.
In the Middle Ages, an acre was defined as the amount of land one man with one ox could plow in one day. It was ultimately defined as being ten chains by one chain, or 660 feet by 66 feet, for a total of 43,560 square feet. An acre was ten times longer than it was wide because it was difficult to turn a plow pulled by an ox. Thus, the furls plowed were long; a long furl of ten chains was called a furlong in old English.
Fast forward a millennia or so when cities and farmland were being platted. 640 square acres equals one square mile, called one section, and a township is six square miles, or 36 sections. A quarter section is 160 square acres, a quarter mile on each side.
Townships were often laid out with a road every mile and cities within townships were often laid out with streets in grids on five acre parcels between the mile roads. The five acre grids were normally a half furlong east-west by one furlong north-south. The main street often ran through the middle of the city running north-south, sometimes called the Main Drag. (I've heard that it got that name from farmers who held contests to see who had the strongest horse or mule by seeing which could drag the heaviest load down the main street, a precursor to today's tractor pulls. That may also be origin of the term 'drag race'. I can't confirm either of these, though.)
A furlong, 660 feet or 220 yards, is an eighth of a mile. One city block wasn't enough length to get up to speed in illegal speed contests between automobiles by the late '40s so the standard became two blocks. Also, some cities had traffic lights that were timed to stop traffic every one or two blocks to keep the speeds down, so getting through the second light before it changed became the challenge.
Two blocks = two furlongs = 1,320 feet = a quarter mile. You get the idea. Racing cars two blocks, or a quarter mile, down the main drag became drag racing.
So if you live in a city that's laid out in a grid, check to see if an east-west block is 1/16th of a mile (or if 16 east-west blocks equals one mile), and if a north-south block is 1/8th of a mile (or if eight north-south blocks equals one mile). If so, now you know why.
Bear in mind that if your car can do 120 MPH in a quarter mile at the track, you can get up to 120 MPH in two city blocks and that's a really bad idea on public roads.
If you're still awake, I hope you found that interesting.
