What does a yellow diamond-shaped sign usually mean?

A warning about a hazard or change in the road ahead

A rule you must obey, such as a speed limit

A nearby service, such as a hospital

An orange diamond sign means:

A work zone or temporary traffic control ahead

A five-sided (pentagon) sign tells you:

You are near a school or school crossing

US Road Signs: Shapes, Colors and What Each Sign Means

US road signs follow one national standard, the federal MUTCD, so their shape and color tell you what kind of message they carry before you can read them. Red means stop, yield or prohibited; yellow warns of a hazard; white with black states a rule; orange marks work zones; green guides you; blue shows services; brown points to recreation. Learn the 8 shapes and 9 colors below, then open any sign for its full meaning.

Updated on 2026-11-06 · Ver en español

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All U.S. road signs

The Stop Sign: What It Means and How to Stop Correctly — What a stop sign means and exactly where to stop: stop line, crosswalk or corner, then who goes first. Rules, test traps and 3 practice questions for the DMV.
The Yield Sign: Slow Down, Give Way, Stop if Needed — What a yield sign means: slow down, be ready to stop and let traffic and pedestrians go first. When you must stop, test traps and 3 DMV practice questions.
The Speed Limit Sign: Maximum Speed, Not a Goal — What a speed limit sign means: the maximum legal speed in good conditions, not a target. Basic speed law, advisory and school limits, and 3 practice questions.
The Do Not Enter Sign: Never Drive Past It — What the do not enter sign means: traffic comes toward you beyond it, so never drive in. Where it is posted, what to do if you miss it, 3 practice questions.
The Wrong Way Sign: You Are Facing Oncoming Traffic — What the red WRONG WAY sign means: you are driving against traffic. How to react safely, how it differs from DO NOT ENTER, and 3 DMV practice questions.
The One Way Sign: Traffic Flows Only in the Arrow's Direction — What the black-and-white ONE WAY sign means, how to turn onto and off one-way streets, left on red rules, test traps and 3 DMV practice questions.
The No U-Turn Sign: Turning Around Is Prohibited Here — What the no U-turn sign means, where U-turns are illegal even without a sign, how to turn around legally, test traps and 3 DMV practice questions.
The No Left Turn Sign: Left Turns Are Prohibited Here — What the no left turn sign means, when time plaques apply, how to reach your destination legally, common test traps and 3 DMV practice questions with answers.
No Turn on Red: When You Must Wait for the Green Light — What the NO TURN ON RED sign means, when right and left turns on red are normally legal, time plaques, the New York City rule and 3 DMV practice questions.
The Keep Right Sign: Stay to the Right of the Obstacle — What the keep right sign means: pass to the right of a median, island or obstacle. Where you see it, keep left signs, test traps and 3 DMV practice questions.
The Do Not Pass Sign: Stay in Your Lane Until It Ends — What the DO NOT PASS sign means, how it relates to solid yellow lines and the yellow no passing zone pennant, where passing is illegal and 3 practice questions.
The School Zone Sign: Slow Down and Watch for Children — What the five-sided school zone sign means, school speed limits, when they apply, school bus and crossing guard rules, test traps and 3 DMV practice questions.
The School Crossing Sign: Children Cross Right Here — What the school crossing sign with a down arrow means, how it differs from the school zone sign, crossing guard and crosswalk rules, and 3 practice questions.
The Railroad Crossbuck: Treat It Like a Yield Sign for Trains — What the white X-shaped railroad crossbuck means, when to stop 15 to 50 feet from the tracks, gates and lights, stalling on tracks and 3 practice questions.
The Railroad Advance Warning Sign: Tracks Ahead — What the round yellow RR sign means: a railroad crossing is ahead. How to slow down, look and listen, RXR markings, test traps and 3 practice questions.
HOV Lane Signs: Who May Use the Carpool Lane, and When — What HOV lane signs and the white diamond mean: minimum occupants (2+ or 3+), hours, who may use the lane, how to enter and exit, and 3 practice questions.
Curve Sign: What It Means and How to Drive the Curve — What the curve ahead sign means, how fast to take the curve, the difference with the turn sign, and 3 practice questions for the DMV permit test.
Winding Road Sign: A Series of Curves Ahead — The winding road sign warns of three or more curves in a row. Learn what it means, how to adjust your speed and lane position, plus 3 practice questions.
Merge Sign: How to Merge, and Who Has to Yield — The merge sign warns that two lanes of traffic will join. Learn who yields, how to merge onto a freeway and how to help merging drivers, plus 3 questions.
Lane Ends Sign: What to Do When Your Lane Disappears — The lane ends sign warns that one lane is about to disappear. Learn which lane ends, who yields, how the zipper merge works and 3 practice questions.
Signal Ahead Sign: Get Ready for a Traffic Light — The signal ahead sign warns of a traffic light you cannot see yet. Learn what it means, how to approach the signal and handle a yellow light, with 3 questions.
Stop Ahead Sign: Prepare to Stop at the Next Intersection — The stop ahead sign warns of a stop sign you cannot see yet. Learn what it means, where to slow down, where to stop at the intersection, plus 3 questions.
Two-Way Traffic Sign: Oncoming Traffic Ahead — The two-way traffic sign warns that the road ahead carries traffic in both directions. Learn how to keep right and when you may pass, with 3 questions.
Divided Highway Sign: A Median Separates Traffic Ahead — The divided highway sign warns that a median will separate the two directions ahead. Learn how to keep right and avoid wrong-way driving, plus 3 questions.
Slippery When Wet Sign: Avoid Skids on Wet Pavement — The slippery when wet sign shows a car with skid marks. Learn what it means, how to avoid skids and hydroplaning, and what to do if you slide, plus 3 questions.
Deer Crossing Sign: How to Avoid Hitting a Deer — The deer crossing sign warns that deer often cross the road. Learn when they are most active, why you should not swerve and what to do after hitting one.
Pedestrian Crossing Sign: When to Yield to People on Foot — The pedestrian crossing sign warns of people crossing ahead. Learn when you must yield or stop for pedestrians and the test traps, plus 3 questions.
No Passing Zone Sign: The Yellow Pennant on the Left — The no passing zone sign is the only pennant-shaped U.S. sign. Learn why it is on the left side of the road and how to pass legally, with 3 questions.
Advisory Speed Plaque: The Yellow MPH Sign Explained — The yellow advisory speed plaque shows a safe speed for a curve or hazard. Learn what it means, how it differs from a speed limit and when to go slower.
Road Work Ahead Sign: How to Drive Through a Work Zone — The orange road work ahead sign marks the start of a work zone. Learn what it means, how to drive through work zones and why fines are often higher there.
Flagger Ahead Sign: How to Follow a Flagger's Signals — The flagger ahead sign warns that a worker is directing traffic in a work zone. Learn what the STOP/SLOW paddle and hand signals mean, with 3 questions.
Interstate Route Sign: Reading the Red and Blue Shield — The red, white and blue Interstate shield marks a route of the Interstate Highway System. Learn how route and exit numbers work and how to drive the freeway.
Hospital Sign: What the Blue H Means for Drivers — The blue sign with a white H points the way to a hospital. Learn what blue service signs mean, how to follow hospital signs and what to do in an emergency.
Roundabout Sign: How to Enter, Yield and Exit — The roundabout sign warns of a circular intersection ahead. Learn who yields, which lane to choose and how to enter and exit safely, plus 3 practice questions.

Road signs quiz: 5 test-style questions

What does a yellow diamond-shaped sign usually mean? A rule you must obey, such as a speed limit / A warning about a hazard or change in the road ahead / Directions to a city or exit / A nearby service, such as a hospital. Answer: A warning about a hazard or change in the road ahead. The diamond is the standard shape for warning signs, and yellow is the general warning color.
Which shape is used only for the railroad advance warning sign? Octagon / Pennant / Circle / Pentagon. Answer: Circle. The round yellow sign with an X and two R letters is the only circular sign: a railroad crossing is ahead.
An orange diamond sign means: School zone ahead / Recreation area / Hospital ahead / A work zone or temporary traffic control ahead. Answer: A work zone or temporary traffic control ahead. Orange is reserved for temporary traffic control in work zones, such as ROAD WORK AHEAD and FLAGGER AHEAD.
A five-sided (pentagon) sign tells you: You are near a school or school crossing / No passing zone / Stop ahead / Interstate route. Answer: You are near a school or school crossing. The pentagon is reserved for school and school crossing signs, usually fluorescent yellow-green.
What does a white rectangular sign with black letters usually show? A warning / A rule or regulation / A tourist attraction / A detour. Answer: A rule or regulation. White with black legend is used for regulatory signs, such as SPEED LIMIT, ONE WAY and DO NOT PASS.

How US road signs work

Every public road in the United States uses signs designed according to the Manual on Uniform Traffic Control Devices (MUTCD), published by the Federal Highway Administration. States may adopt their own supplement, but the basic shapes, colors and symbols are the same from Maine to Hawaii. That is why the permit test in every state includes road sign questions, and why a sign learned in Texas means the same thing in New York.

Signs are built so you can understand them in layers. From far away, you see the shape. Closer, you see the color. Only then can you read the symbol or words. If you know the shape and color code, you already know whether the sign gives an order, warns you of a hazard or gives directions, which buys you precious seconds at highway speed.

The MUTCD sorts signs into three main classes: regulatory signs (laws you must obey), warning signs (hazards and changes ahead) and guide signs (routes, destinations, services and recreation). School, railroad and work zone signs are special families with their own shapes and colors. The guide below covers each family, and the grid at the bottom of this page links to a detailed page for every common sign.

The 8 sign shapes and what they mean

Some shapes are reserved for a single sign, so you can identify it even from behind or when it is covered by snow. These are favorite test questions.

Crossbuck (X): the white railroad crossbuck at the tracks, which means yield to trains.
Shields: route markers, such as the red, white and blue Interstate shield and the black-and-white US route shield.
Trapezoid: some recreational and national forest route markers.

US road sign shapes and their meanings
Shape	Meaning	Example
Octagon (8 sides)	Stop: used only for the STOP sign	Stop sign
Triangle pointing down	Yield: used only for the YIELD sign	Yield sign
Circle	Railroad crossing ahead (advance warning)	Railroad advance warning
Pennant (sideways triangle)	No passing zone, posted on the left side of the road	No passing zone
Pentagon (5 sides)	School zone or school crossing	School zone sign
Diamond	Warning: hazard or change in the road ahead	Curve ahead
Vertical rectangle	Regulatory: a rule you must obey	Speed limit
Horizontal rectangle	Guide information, and some regulatory and warning messages	One way

The 9 sign colors and what they mean

Color tells you the family of the message. The MUTCD defines the colors below; two more appear occasionally: fluorescent pink for incident management (crash scenes) and purple for lanes reserved for electronic toll accounts.

US road sign colors and their meanings
Color	Meaning	Examples
Red	Stop, yield or prohibition	STOP, YIELD, DO NOT ENTER, WRONG WAY, red circle and slash
Black	Regulation (with white), and the legend of most signs	ONE WAY background, symbols on regulatory and warning signs
White	Regulation	SPEED LIMIT, KEEP RIGHT, DO NOT PASS, NO TURN ON RED
Yellow	General warning	Curves, merges, signal ahead, deer crossing
Orange	Temporary traffic control in work zones	ROAD WORK AHEAD, FLAGGER AHEAD, detours
Fluorescent yellow-green	School, pedestrian and bicycle warnings	School zone, school crossing, pedestrian crossing
Green	Directions and guidance; permitted movements	Exit and destination signs, mileposts
Blue	Motorist services and evacuation routes	Hospital, gas, food, lodging, rest area
Brown	Recreation and cultural interest areas	State and national parks, campgrounds

Regulatory signs: rules you must obey

Regulatory signs tell you what the law requires at that spot. Ignoring them is a traffic violation. Most are white rectangles with black legend; stop, yield and prohibitions use red. The red circle with a diagonal slash means the action shown is not allowed.

The most tested regulatory signs are the stop sign, the yield sign, the speed limit sign, do not enter and wrong way, the one way sign, turn prohibitions such as no U-turn, no left turn and no turn on red, and lane rules such as keep right, do not pass and HOV lane signs.

Warning signs: hazards ahead

Warning signs are usually yellow diamonds with black symbols. They do not create a new rule; they tell you to slow down and be ready for a change: a curve or winding road, a merge or lane ending, a traffic signal or stop sign ahead, two-way traffic, a divided highway, a road that is slippery when wet, or a deer crossing.

A small yellow plaque below a warning sign may show an advisory speed: the speed recommended for that curve or ramp in good conditions. It is not the legal limit, but driving faster is risky and can be used as evidence that you were driving too fast for conditions.

Guide, service and recreation signs

Guide signs help you find your way. Green signs show exits, destinations, distances and mileposts. Route markers use shields: the Interstate shield is red, white and blue, US routes use a white shield on black, and each state has its own design. On Interstates, even route numbers usually run east-west and odd numbers north-south.

Blue signs point to services such as gas, food, lodging, rest areas and the hospital. Brown signs lead to parks, historic sites and recreation areas. These signs are informational: they rarely appear as rules on the test, but you may be asked what their colors mean.

School, railroad and work zone signs

Three families protect the most vulnerable places on the road, and each has its own look:

School: fluorescent yellow-green pentagons. The school zone sign warns of a school ahead and often comes with a lower speed limit when lights flash; the school crossing sign adds a downward arrow at the crosswalk. The same color is used for the pedestrian crossing sign.
Railroad: the round yellow advance warning sign comes first; the white crossbuck stands at the tracks. When a train is coming, stop 15 to 50 feet from the nearest rail.
Work zones: orange diamonds and rectangles such as road work ahead and flagger ahead. Obey flaggers, slow down and expect lane shifts; many states increase fines in work zones when workers are present.
Roundabouts: before a circular intersection, a yellow roundabout sign warns you to slow down and yield to traffic already circulating.

How to study road signs for the permit test

Most state knowledge tests include a set of road sign questions, and some states give a separate sign test that you must pass on its own. The fastest method is to learn the shape and color codes first, then the signs that have a unique shape (stop, yield, railroad, no passing, school), and finally the common warning symbols. For each sign, ask yourself two questions: what does it mean and what do I do.

Use the grid below to review each sign with its picture, then test yourself with our road sign test questions and the topic practice tests. Our road signs test guide explains how sign questions are asked, and the traffic lights and pavement markings guide covers the lines and signals that work with signs. State rules on the test format are on your state page, for example the California or Texas permit test.

Quick rule of thumb: red = stop or don't, white = rule, yellow = warning, orange = work zone, yellow-green = school and pedestrians, green = go this way, blue = services, brown = recreation.

Road signs FAQ

How many road signs are on the DMV permit test?

It depends on the state. Most knowledge tests mix several sign questions with rules-of-the-road questions, and a few states give a separate road sign test. Your state page lists the format.

What are the three main types of road signs?

Regulatory signs (rules you must obey), warning signs (hazards ahead) and guide signs (directions, services and recreation). School, railroad and work zone signs are special families.

What does each sign color mean?

Red: stop, yield or prohibited. White and black: regulations. Yellow: warning. Orange: work zones. Fluorescent yellow-green: schools, pedestrians and bicycles. Green: directions. Blue: services. Brown: recreation.

Which signs have a unique shape?

The stop sign (octagon), the yield sign (downward triangle), the railroad advance warning sign (circle), the no passing zone sign (pennant) and school signs (pentagon).

Are road signs the same in every state?

Yes, in their design: all states follow the federal MUTCD. Some rules behind the signs, such as default speed limits or turn-on-red details, can vary by state.

What is the difference between a warning sign and a regulatory sign?

A regulatory sign states a law, such as a speed limit or a turn prohibition. A warning sign alerts you to a hazard, such as a curve, so you can adjust; it does not create a new rule by itself.

What is the best way to memorize road signs?

Learn shapes and colors first, then the signs with unique shapes, then common warning symbols. Practice with picture-based questions until you can name each sign and the action it requires.