Why Are Highway Signs Usually Green?

Published Categorized as Infrastructure
Green Highway Signage

One thing many drivers have never considered is that road signs are designed to be different colors intentionally. We all know of traffic lights being specific colors, but what about other road signs? Many of us may wonder, why are highway signs usually green?

Highway signs are designed to be green to help provide guidance to the driver. Green signs provide less crucial information to drivers and are used for directions. The reason is that green is a cool color and doesn’t draw attention like yellow or red signs, which can be distracting on the highway.

The last thing you want is to get lost on the highway and miss your turn. That’s why it’s good to learn about the different highway signs. Don’t worry, as we will provide you a basic rundown of highway signs and their color.

Green Signs Are Reassuring

There is a science behind why highway signs are green.

When you think of colors on the color spectrum, which ones stand out the most? If you were walking outdoors, would you be more likely to look at a red balloon floating in the air or a green one?

In most cases, people’s attention would be drawn to the red balloon because red stands out more against the surrounding environment. Red is not often a color you see in nature, making it more likely to notice it.

Using the same theory, green signs are used to draw only slight attention while driving.

Being on a highway is already hazardous because of the high-speed limits. When traveling, you must keep your eye on the road at all times. For brief moments, you may ask yourself where you want to go, how close you are, and which exit to take.

While you could use a GPS, it can be frustrating because standard GPS doesn’t give you enough warning to get into other lands before the exit arrives. That’s why road signs will be your next best friend.

They are designed to provide valuable information to the driver ahead of the turn.

Green is also a very soothing color, which won’t distract from driving. You can glance over and look at it, but it won’t cause you to quickly look over if it was a red sign which stands out. Hence, green signs are used on the highway.

Types of Road Signs

There are multiple road signs with many shapes and colors to help drivers navigate the open road.

Color is the most critical factor because they help drivers understand when to stop or go. Aside from that, specific colors are already pre-programmed into driver’s minds to help them identify what driving action they need to take.

Below, we’ve provided a list of what each color sign means. However, there are still plenty of other types of signs you may run into. Not all signs may show up where you live due to different environmental road conditions. The Road Traffic Signs website gives an excellent breakdown of all types of sign colors you could run into.

Here are the different types of road signs you’d come across out on the open road:


Regulatory road signs come in red, black, and white to remind drivers of the rules of the road.

Each sign also has a specific shape that helps the driver quickly identify what the sign wants them to do. For example, an octagon-shaped sign that is colored red immediately reminds you to stop without reading the sign.

These types of cues are pre-programmed into our head through our permit training and also from day-to-day driving. A red and white sign that says yield will prompt you to slow down while the wrong-way indicator tells you where you can and can’t drive.

Highway signs are very similar, as their color indication enables you to understand where you can and can’t go.


A yellow sign indicates to the driver to use caution and look out for danger. The color of these signs attracts attention but isn’t so alarming that they immediately draw your eye.

These types of signs are found in residential areas.

The zones you’ll find them in are:

  • School zones
  • Neighborhoods
  • On the highway

These indicate merging, railroads, road directions, or animals are present. However, in some cases where a warning sign won’t be yellow, which is when the warning sign is temporary.


Road signs that are blue, black, or green provide information to the driver.

Examples include a blue sign to signal travel services, emergency evacuation routes, and route markers. A black sign will convey night speed limits, one-way traffic, and trucking signs. Lastly, green signs are used for information or parking signs.


The last road sign type you’ll run into is a construction sign represented by an orange background.

These signs are orange to draw attention to the sign and the surrounding area. The indicators are usually temporary and digital and provide information on construction hazards, alerts, road closed, or other conditions.

Orange road signs can be mistaken for coral color road signs, which may be confusing.

Coral signs are used to reserve a sign for future use. If you don’t see any writing on the sign, it’s not orange but instead coral and won’t have any information you can use.

Green vs. Fluorescent Yellow-Green Signs

There are two types of green signs you’ll see on the highway. It’s essential to be able to identify what each color means. Green is known to be cooling and calming, hence drawing less attention to it.

However, the information written on the sign will help guide you out on the road.

Let’s look at a breakdown of the similarities and differences between a green and a fluorescent yellow-green traffic sign.

Green Signs

Regular green signs are used as a background color for signs that guide or provide information. They are also used for the legend on permissive regulation and parking signs. Due to this, they play a significant role on a highway.

On a highway, green signs provide three types of information:

  1. The first type of information a green sign will show you is where you are, your exact location.
  2. The second type of information will tell you which way to go towards a particular destination.
  3. The last type will notify you of the distance you’ve traveled and the distance to your following location.

Fluorescent Yellow-Green Signs

Fluorescent yellow-green signs provide you information about pedestrians, bicycles, and schools.

These are often tinted yellow to help bring more attention to the sign. They don’t stand out as much as orange, yellow, or red. However, they draw your eye to them more so than green, blue, or purple.


As you can see, there are plenty of reasons as to why highway signs are green. They are eye-catching but not as distracting as other road sign colors.

They also allow you to quickly tell where you are, what’s around you, and distances.

The Traffic Engineering Manual is an excellent place to find more information if you’re not familiar with green road signs. Aside from that, remember that green is meant for directions and that there are yellow-green signs.

Hopefully, we’ve helped you learn a bit more about safe driving on the highway.


By Giovanni Valle

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

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