Sign Colors, Shapes, and Symbol Meanings
Sign colors and shapes form a language you can read before you see the words. The Connecticut exam tests the national MUTCD system: red means stop or prohibit, white means regulatory, yellow means warning, orange means work zone, green means guide, blue means services, brown means recreation and culture, and fluorescent yellow-green means school or pedestrian. Shapes add a second clue.
Core rules
- Octagon: STOP. Inverted triangle: YIELD. Diamond: warning. Pennant: no-passing zone. Round: railroad advance warning. Crossbuck: railroad crossing. Pentagon: school zone or school crossing.
- Red circles with a diagonal slash mean prohibited. A red arrow or red slash over a symbol means no turn or no movement.
- White rectangles with black legends are regulatory: speed limits, lane use, parking rules. Green rectangles are guide signs; blue rectangles are services; brown rectangles are recreation.
- Yellow diamonds warn; orange diamonds or rectangles are temporary work-zone devices.
- Symbols can carry the message without English: a curved arrow means curve ahead, a merge arrow means lane ends, a pedestrian symbol means crossing, and a bicycle symbol means bicycle traffic.
Worked example
You see a blank diamond-shaped sign with a black symbol of a road narrowing on the right. You do not need to read a word. The diamond tells you it is a warning, and the symbol tells you the right side is closing or narrowing. Slow down and move left if it is safe. If the same symbol appeared in an orange diamond, it would still warn of a narrowing, but the orange color would tell you the condition is temporary, likely work-related.
Traps
Do not rely on color alone; a red sign can be a stop sign or a prohibition sign. Do not confuse a yellow warning diamond with an orange work-zone diamond. Do not treat a green guide sign as a regulatory command. Do not assume a round sign is a railroad crossing sign unless it has the X and R symbol. Do not ignore the slash on a prohibition sign.