Traffic Signs, Signals, and Road Markings
Illinois uses standard national sign shapes and colours, and the permit test shows you images and pavement markings and asks what they require. Learn the shape first - it tells you the category even before you read the words.
Shapes and colours
- Octagon, red: stop.
- Inverted triangle, red and white: yield.
- Diamond, yellow: warning - curves, intersections ahead, surface changes.
- Pennant, yellow: no-passing zone begins here.
- Round, yellow: railroad advance warning; the X-shaped crossbuck marks the crossing itself.
- Vertical rectangle: regulatory (white with black, or red and white). Green is guidance, blue is services, brown is recreation, fluorescent yellow-green marks schools and pedestrians.
Signals
A flashing red means stop, then proceed when clear - treat it as a stop sign. A flashing yellow means slow down and proceed with caution; it never gives you the right of way. A red arrow prohibits that movement; a green arrow protects it. Right turn on red is allowed after a complete stop unless a sign forbids it. Left turn on red is allowed only from a one-way street onto another one-way street.
Pavement markings
Yellow lines separate traffic moving in opposite directions; white lines separate lanes moving the same way. Broken lines may be crossed; double solid lines may not. Where a solid and a broken line pair up, the line on your side controls you - broken on your side means you may pass.
Worked example
You approach a rural two-lane road with a double yellow centre line. The broken line is on the opposite side. That means oncoming traffic may pass but you may not, even with an empty road ahead - the marking is assigned by lane, not by opportunity.
Traps that cost marks
Confusing a flashing yellow with a flashing red; reading a pennant as a general warning sign; treating left-on-red as legal from any street.