Road Signs & Traffic Signs in the US: The Definitive Guide

by Zutobi · Updated Jul 08, 2022

When you’re driving down the street, it’s hard not to notice the many road signs along US city and suburban streets. While a few of them are quite self-explanatory, the majority may require a bit of explanation to fully understand. Knowing your road signs is not only important for your knowledge of driving, but for the written test as well.

As you may have noticed, these road signs come in a variety of different sizes, shapes, and colors. Each of these characteristics has its own distinct meaning and will help you understand what to expect while driving your motor vehicle. After reading this article, you’ll never ponder over a US traffic sign again!

In this article, we’ll cover:

  • Colors and shapes
  • The most important types of road signs

Colors of Road Signs

The color of a road sign tells you a lot about it. This is because certain colors only mean one thing. For example, yellow is reserved for warning signs.

colors of US road signs

Shapes of Traffic Signs

Shapes also tell you a lot about a road sign. Some shapes are only used for one type of sign. For example, you will never see an octagon-shaped sign being used for anything else than to indicate a stop sign.

diamond-shaped sign and pennant-shaped sign on white background

Diamond – Warning

Diamond signs are used exclusively to warn drivers of upcoming hazards or circumstances that may require additional attention. Construction zones can be identified with an orange, diamond sign.

Pennant – No Passing Zone

Pennant-shaped signs always indicate a no-passing zone. These signs are common on rural roads with one lane of traffic traveling in each direction. No passing zones are usually placed to indicate limited visibility of oncoming traffic due to road conditions.

octagon-shaped sign and triangle-shaped sign on white background

Octagon – Stop

When approaching an octagonal traffic sign, you will be required to come to a stop. Stop signs are always octagonal and red, making them very difficult to miss while on the road.

Equilateral Triangle – Yield

Like the octagon, the equilateral triangle road sign only indicates one action – to yield. Yield signs are always red and triangle-shaped.

pentagon-shaped sign and rectangle-shaped sign on white background

Pentagon – School or County Marking

Pentagon shapes are often used to warn you of upcoming school or county zones. School zone markings are always pentagonal in shape and fluorescent yellow or green in color. County markings are pentagonal in shape; however, their color can vary depending on the state.

Rectangle, Square (often vertical) – Regulatory

These signs are often rectangle with the longer direction vertical and say what you must or must not do. We will go through these signs in more depth below.

crossbuck-shaped sign and round-shaped sign on white background

Crossbuck and Round Signs – Railroad Crossing

Railroad crossing signs are hard to miss. They are often circle or crossbuck and read the words ‘railroad crossing’ in large letters. Before crossing the tracks, be sure to look both ways to avoid being struck by an oncoming train.

interstate sign and Rectangle-shaped sign on white background

Interstate Highway

Indicates the route number of the Interstate highway.

Rectangle, Square (often horizontal) – Guide

These signs are often rectangle with the longer direction horizontal and provide guidance information.

What are the Most Important Types of Signs?

The majority of these shapes and colors are found in the most common 3 types of signs – regulatory, warning, and guide signs. We’ll now go through these 3 in-depth.

Regulatory Signs

Regulatory signs are black or white and are meant to remind motorists about traffic laws that exist on the current street. These types of signs come in several shapes and are usually enforced at all times, meaning that they must be followed.

Types of Regulatory Signs

There are two types of regulatory signs – they can either tell you what you must do (mandatory) or what you must NOT do (prohibitory).

Examples: Speed limit signs, road closure signs, one-way signs.

Type 1 – Mandatory

Used when drivers are required to carry out a designated task, such as turning or keeping a minimum speed. They are not suggestions, but rather instructions you must follow in order to keep traffic flowing properly. Examples include minimum speed signs, keep ahead signs, and left/right turn only signs.

Type 2 – Prohibitory

Designed to prohibit or restrict certain types of vehicles or maneuvers to prevent accidents. Generally includes a red circle with a diagonal line going through it. Examples include no turning signs, no-entry signs, and no parking signs.

Color of Regulatory Signs

Black or/and white. There are only a few exceptions, such as the stop sign and the yield sign. Red is used to indicate when a driver needs to stop or yield for oncoming traffic, or when something is prohibited. As the color red is often linked to alertness, it is used very sparsely on the road.

Regulatory One-Way Sign

Warning Signs

Warning signs are used to alert motorists of possible hazards that may be approaching or circumstances that may not be easily spotted. These are almost always yellow signs but can come in a variety of different shapes and sizes.

Examples: Pedestrian crossing sign, animal crossing ahead, winding road ahead, and speed bumps ahead.

Color of Warning Signs

Generally yellow. Can also be orange, which warns you of certain construction hazards. Orange construction signs are usually placed to indicate the presence of construction workers operating on the road and often come with reduced speed requirements. In many places, this is considered an ‘active work zone’.

Guide Signs

Some traffic signs are meant to guide drivers along highways and county roads. They commonly display information such as mile markers and upcoming entry and exit points on highways. Examples of guide signs include rest stop signs, route number signs, recreational signs, highway entry, and exit signs.

Color of Guide Signs

Generally blue and/or green. Can also be brown, which indicates natural parks and other recreational sites around the United States. If you’re an adventure lover, these brown signs will lead you to some of the most beautiful sights this country has to see.

Examples: Hiking trail signs, national park signs

Take our full course with tests and theory

550+ exam-like questions

All you need to ace your test

Perfect for first-timers, renewals and senior citizens

Ace your DMV test, guaranteed