Sign Shapes, Colors, and Symbol Recognition
Shape and color let you identify a sign before you can read it. The exam tests that instant recognition, plus the symbol families that repeat across Idaho roads.
Shapes
- Octagon: STOP, the only octagonal sign on the road.
- Inverted triangle: YIELD.
- Pennant (horizontal triangle): no-passing zone.
- Diamond: warning.
- Round: railroad advance warning.
- Crossbuck (X): railroad crossing.
- Pentagon: school zone or school crossing.
- Rectangle: regulatory or guide, depending on color.
Colors
- Red: stop, yield, prohibition, or wrong-way.
- Yellow: warning; fluorescent yellow-green for pedestrians, bicyclists, and school areas.
- Orange: temporary work zone.
- Green: destinations, distances, exits.
- Blue: motorist services.
- Brown: recreation and cultural points.
- White with black: regulatory.
Symbols
- A symbol inside a red circle with a slash prohibits that action.
- A symbol on a yellow diamond warns of that condition ahead.
- Direction arrows, lane arrows, and route shields tell you where the lane or road goes.
Worked example
A fluorescent yellow-green diamond shows a walking figure. The diamond says warning; the fluorescent yellow-green says pedestrian or school area. So it warns of a pedestrian crossing ahead. It does not itself create a marked crosswalk or require a stop unless a pedestrian is present.
Traps
Confusing the pennant with the yield triangle; assuming every round sign is a railroad crossing, when round marks only the advance warning; confusing brown recreation signs with green guide signs; treating a yellow warning symbol as a legal prohibition.