Short answer: You can read most road signs before you are close enough to see the words. Shape and color tell you the type of sign: red means stop or “you can’t,” yellow warns you about what is ahead, orange marks road work, and white rectangles state a rule you must obey. Use this cheat sheet to learn what each common California sign means and what to do when you see it.
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Start the free test →Sign shapes and what they mean
Some shapes are saved for just one sign, so you know what it says even when it is covered in dirt or snow. These shapes come from the federal Manual on Uniform Traffic Control Devices (MUTCD), which sets the standards for U.S. road signs.
| Shape | Meaning |
|---|---|
| Octagon (8 sides) | STOP. Used only for the stop sign. |
| Triangle, point down | YIELD |
| Circle | Railroad crossing ahead (advance warning) |
| X (crossbuck) | Railroad crossing. Used only for this sign. |
| Pentagon (5 sides) | School zone or school crossing (also county route markers) |
| Pennant (sideways triangle) | No passing zone |
| Diamond | Warning about road conditions or hazards ahead |
| Rectangle or square | Rules (regulatory), directions (guide), and some warnings |
Sign colors and what they mean
The MUTCD gives each color a general meaning. Learn these and you can guess the purpose of a sign you have never seen.
| Color | Meaning |
|---|---|
| Red | Stop or prohibition (something you may not do) |
| White (with black) | Regulation: a rule you must follow |
| Yellow | Warning |
| Fluorescent yellow-green | Pedestrian, bicycle, playground, school bus, and school warnings |
| Orange | Temporary traffic control, such as road work |
| Green | Movements allowed and direction guidance |
| Blue | Road user services, tourist information, and evacuation routes |
| Brown | Recreation and cultural interest areas, such as parks |
Regulatory signs: rules you must obey
The California Driver’s Handbook says red and white signs tell you what to do, and a white rectangular sign “communicates many important rules you must obey.”
Stop. Make a full stop at the limit line or before the crosswalk. If there is no line or crosswalk, stop before the intersection. Then check traffic in all directions before you go.
Yield. Slow down and be ready to stop to let any vehicle, bicyclist, or pedestrian pass before you go.
Do Not Enter. Do not enter the road or ramp where the sign is posted.
Wrong Way. You are driving against traffic. When it is safe, back out or turn around. At night, red reflectors shining back in your headlights also mean you are going the wrong way.
One Way. Traffic moves only in the direction of the arrow. U-turns are not allowed on one-way streets. To turn left from a one-way street onto another one-way street, start in the far-left lane.
Speed Limit. This is the most you may drive in good conditions. California’s Basic Speed Law says you may never drive faster than is safe for current conditions, so slow down in heavy traffic or bad weather. Unless a sign says otherwise, the limit is 25 mph in business and residential areas and 65 mph on most highways.
No U-Turn. A red circle with a red line through a picture means you cannot do what the picture shows. Here, that is a U-turn.
No Left Turn. Same red circle and line: left turns are not allowed here. Go straight or turn right and find another route.
No Turn on Red. Normally you may turn right on a red light after a full stop, if you yield to pedestrians and it is safe. This sign takes that choice away, so wait for the green light.
Keep Right. Pass to the right of the island, divider, or object ahead.
Warning signs: slow down and get ready
Most warning signs are yellow diamonds. They warn you about road conditions and dangers ahead. The handbook says to obey all warning signs, whatever their shape or color.
Merge. Another lane of traffic joins yours ahead. Make room for drivers merging in, even if you have the right-of-way. If you are the one merging, blend in when it is safe and don’t stop unless you must.
Lane Ends. Your lane is ending. Look for a gap, signal, and move over early. Ending lanes are often marked with large broken lines on the road.
Curve to the Right. The road bends right ahead. For sharp curves, slow down as you approach and keep your speed down through the curve.
Slippery When Wet. The road gets slick when wet. On a wet road, reduce your speed by 5 to 10 mph. The first rain after a dry spell is extra slippery because oil and dust come up from the pavement.
Signal Ahead. There is a traffic light ahead. Be ready to stop if it turns yellow or red. If a signal is not working, stop as if there were stop signs in all directions.
Stop Ahead. A stop sign is coming up. Start slowing down now so you can make a full stop.
Divided Highway. The road ahead is split by a median or barrier. Stay to the right of the divider.
Two-Way Traffic. Traffic ahead will be coming toward you in the other lane. A single solid yellow line marks the center of a road with two-way traffic.
Pedestrian Crossing. Watch for people crossing. Pedestrians have the right-of-way in marked or unmarked crosswalks, and you must not pass a vehicle stopped at a crosswalk.
School and railroad signs
School. The five-sided sign means you are near a school. Drive slowly and stop for children in the crosswalk. The speed limit is 25 mph within 500 feet of a school while children are outside or crossing the street.
Railroad Crossing Ahead. This round sign warns of train tracks ahead. Look, listen, slow down, and prepare to stop. The speed limit is 15 mph within 100 feet of a crossing where you can’t see the tracks for 400 feet in both directions, unless the crossing has gates, a warning signal, or a flagger.
Railroad Crossbuck. The X-shaped sign marks the crossing itself. Let any trains pass before you go. If lights, gates, or a person signal that a train is coming, stop at least 15 feet from the nearest track. If your car ever stalls on the tracks, get out right away. If a train is coming, move away from the tracks at an angle toward the direction the train is coming from, then call 911. If no train is coming, call the number posted on the crossing post or metal control box, then call 911.
Construction and work zone signs
Road Work Ahead. Orange signs mark work zones. Slow down, leave extra space, and expect sudden stops and lane changes. Fines are doubled in highway construction or maintenance zones when workers are present, and work zone fines can be $1,000 or more. You must also move over and slow down for emergency and road work vehicles.
Carpool, bike, and parking signs
HOV (carpool) lane. A diamond symbol marks a high-occupancy vehicle lane, reserved for carpools, buses, and motorcycles. Clean Air Vehicle decals that once let some low-emission cars drive alone in carpool lanes stopped being valid on October 1, 2025, after the federal program ended. Signs at the on-ramp or along the road tell you the minimum number of people and the hours the rules apply.
Bike Lane. This lane is for bicyclists only. It is usually marked with a solid white line. To turn right, check your blind spot and enter the bike lane no more than 200 feet before the turn. When passing a bicyclist, leave at least three feet.
Disabled Parking. This space, and any blue curb, is only for a disabled person or someone driving a disabled person, with a special placard or license plate. Never park in the crosshatched area next to the space.
How to study for the road signs test
Road signs are part of the California knowledge test, but the DMV does not publish how many sign questions you will get. If you take the written test in a language other than English, the DMV says you must also take a separate traffic signs test.
- Learn the shape and color tables above first. They cover most questions about signs you don’t recognize.
- Cover the text on this page and say what each sign means and what you would do.
- Read the signs part of the California Driver’s Handbook. Our handbook study guide shows which sections matter most.
- Check yourself with real practice. Take the free 10-question practice test to see where you stand.
You need 80% to pass the knowledge test, so signs are an easy place to pick up points. For more tips, see how to pass the California permit test.
Road rules change from year to year. For the latest, read our summary of new California driving laws for 2026.
Ready to check what you know? Take the free 10-question California permit practice test.
Start the free test →Frequently asked questions
What do the shapes of road signs mean?
An octagon is always a stop sign, a downward triangle means yield, a circle warns of a railroad crossing ahead, an X marks the crossing itself, a pentagon means a school zone, a pennant means no passing, a diamond is a warning, and rectangles show rules or directions.
What does a yellow diamond sign mean?
It warns you about a road condition or hazard ahead, such as a curve, a merge, or a slippery road. Slow down and get ready to react.
What does an orange sign mean?
Orange signs mark road work and other temporary traffic control. Slow down and watch for workers. In California, fines are doubled in highway construction or maintenance zones when workers are present.
Is there a separate road signs test at the California DMV?
Road signs are covered on the regular knowledge test. The DMV says that if you take the written test in a language other than English, you must also take a traffic signs test.
What does a red circle with a line through it mean?
It means the action shown in the picture is not allowed, such as a U-turn or a left turn.
What should I do at a yellow round railroad sign?
It means train tracks are ahead. Look, listen, slow down, and prepare to stop. Let any trains pass before you cross.
Sources
- California Driver's Handbook, Section 7: Laws and Rules of the Road
- California Driver's Handbook, Section 7 (continued): speed limits, railroad crossings, work zones, bike lanes
- California Driver's Handbook, Section 6: Navigating the Roads
- California Driver's Handbook, Section 6 (continued): parking and curb colors
- California Driver's Handbook, Section 8: Safe Driving
- California Driver's Handbook, Section 8 (continued): speed limits
- California DMV: Senior Drivers (traffic signs test with foreign-language written test)
- MUTCD 11th Edition, Chapter 2A (Section 2A.05 sign shapes)
- MUTCD 2009 Edition, Chapter 1A (Section 1A.12 color code)
- DMV: Federal government ends Clean Air Vehicle (CAV) decal program