Zachary Crockett

The words on these guide signs are almost always set in mixed case, with initial capitals followed by lowercase letters. There's a good reason for that.

The words on these guide signs are almost always set in mixed case, with initial capitals followed by lowercase letters. There's a good reason for that.

There are also guidelines around the size of the font on highway signs. And from below, it's hard to grasp just how big the characters are.

There are also guidelines around the size of the font on highway signs. And from below, it's hard to grasp just how big the characters are.

There are also guidelines around the size of the font on highway signs. And from below, it's hard to grasp just how big the characters are.

Then there's the color of the sign. In the 1950s, the federal government looked into the legibility of black, blue, and green signs. Officials staged a test with hundreds of motorists on a road in New York and found that 58% of drivers preferred green. Turns out, the color green has another benefit, too.

Then there's the color of the sign. In the 1950s, the federal government looked into the legibility of black, blue, and green signs. Officials staged a test with hundreds of motorists on a road in New York and found that 58% of drivers preferred green. Turns out, the color green has another benefit, too.

Then there's the color of the sign. In the 1950s, the federal government looked into the legibility of black, blue, and green signs. Officials staged a test with hundreds of motorists on a road in New York and found that 58% of drivers preferred green. Turns out, the color green has another benefit, too.

It provides the best base for retro-reflectivity, basically what makes signs legible when they're illuminated by a car's headlights in the dark. The reflectivity of signs has come a long way. Engineers initially used something called cat's eyes, tiny marbles embedded in each letter on the sign. These have since been replaced by reflective sheeting that covers the whole sign.

It provides the best base for retro-reflectivity, basically what makes signs legible when they're illuminated by a car's headlights in the dark. The reflectivity of signs has come a long way. Engineers initially used something called cat's eyes, tiny marbles embedded in each letter on the sign. These have since been replaced by reflective sheeting that covers the whole sign.

It provides the best base for retro-reflectivity, basically what makes signs legible when they're illuminated by a car's headlights in the dark. The reflectivity of signs has come a long way. Engineers initially used something called cat's eyes, tiny marbles embedded in each letter on the sign. These have since been replaced by reflective sheeting that covers the whole sign.

Now, not every sign on the freeway is green. Some of them are brown. Those are typically used for tourist attractions or recreation points like state parks. And every now and then, you'll also see a blue sign full of corporate logos. Those are called service signs, and their purpose is to tell you what kinds of services and businesses are coming up.

Now, not every sign on the freeway is green. Some of them are brown. Those are typically used for tourist attractions or recreation points like state parks. And every now and then, you'll also see a blue sign full of corporate logos. Those are called service signs, and their purpose is to tell you what kinds of services and businesses are coming up.

Now, not every sign on the freeway is green. Some of them are brown. Those are typically used for tourist attractions or recreation points like state parks. And every now and then, you'll also see a blue sign full of corporate logos. Those are called service signs, and their purpose is to tell you what kinds of services and businesses are coming up.

Say, a Chevron gas station in two miles or an Arby's at the next exit. These are actually ads, and businesses pay for the real estate.

Say, a Chevron gas station in two miles or an Arby's at the next exit. These are actually ads, and businesses pay for the real estate.

Say, a Chevron gas station in two miles or an Arby's at the next exit. These are actually ads, and businesses pay for the real estate.

To qualify, a business usually has to fall into one of a number of categories, gas, lodging, food, camping, attraction, or pharmacy. And the fees vary from state to state. In Arizona, a placement can range from $1,100 in a less populated area to more than $6,000 in a busier urban location. In other states, like North Carolina, it might only be a few hundred bucks.

To qualify, a business usually has to fall into one of a number of categories, gas, lodging, food, camping, attraction, or pharmacy. And the fees vary from state to state. In Arizona, a placement can range from $1,100 in a less populated area to more than $6,000 in a busier urban location. In other states, like North Carolina, it might only be a few hundred bucks.

To qualify, a business usually has to fall into one of a number of categories, gas, lodging, food, camping, attraction, or pharmacy. And the fees vary from state to state. In Arizona, a placement can range from $1,100 in a less populated area to more than $6,000 in a busier urban location. In other states, like North Carolina, it might only be a few hundred bucks.