Yes, there is a method to the madness to naming our roads.

TTstudio/shutterstockWhy does every home and business address end with a specific classification, such as street or lane? Odds are, you probably haven’t thought twice about it until now. But as it turns out, there are certain norms that urban designers follow practically everywhere—even if there isn’t necessarily a specific protocol.

For starters, an ordinary “road” generally describes any throughway that connects two points. “Streets,” on the other hand, are public roads that have buildings on both sides. So while a street is a road, not all roads are streets. Make sense so far?

Now, streets often run perpendicular to “avenues,” which have trees or buildings on both sides, as well. But if they’re so similar, how can you tell the difference between streets and avenues? It usually has to do with the direction they run.

While the grid-like pattern of streets and avenues is nearly universal, the cardinal directions that avenues and streets run vary by city. For example, in Denver, streets run north-south and avenues run east-west. In Manhattan, however, avenues run north-south and streets run east-west. There are exceptions, of course; in Washington, D.C., avenues run diagonal to the street grid, Mental Floss reports.

And if that doesn’t boggle your mind, try this: There are different kinds of streets and roads, too. A “boulevard,” for example, is a wide street with trees on both sides and a median in the center. Smaller roads, such as “ways,” “lanes,” and “drives,” tend to split off from a major road. And both “places” and “courts” are roads with dead ends, but courts usually end in a cul-de-sac. (Regardless of where you’re driving, you’ll definitely want to slow down for these funny road signs.)

To see these differences visually, check out Vox’s video below. And now that we’ve settled that, why are traffic lights red, yellow, and green?

[Source: Mental Floss]