Traffic Signs and Signals
Read the sign's shape and color first
Oregon questions often test whether you can identify a sign's purpose from its shape and color before you read a single word. Octagons are always stop signs; inverted triangles always mean yield; diamonds warn of hazards ahead; pennants mark no-passing zones; round signs mark railroad crossings; and five-sided signs mark school zones. Color carries meaning too: red means stop or prohibit, yellow warns, fluorescent yellow-green marks pedestrian and school warnings, orange marks construction and work zones, and green guides you to destinations.
Signals and their default rules
A steady red light means stop and remain stopped until green. A steady yellow light warns that the signal is about to turn red - you should stop if you can do so safely, not speed up. A flashing red is treated exactly like a stop sign. A flashing yellow means proceed with caution. A green arrow gives you a protected turn, but only in the direction of the arrow. Oregon also allows a left turn on a steady red only when you are turning from a one-way street onto another one-way street, after a full stop, and only if no sign prohibits it.
Traps to watch for
Questions love the near-misses: confusing a warning diamond with a regulatory sign, assuming a flashing yellow means stop, or forgetting that a yellow light does not create a legal right to clear the intersection. Another common trap is the right turn on red - legal in Oregon after a complete stop unless a sign says otherwise - versus the much narrower left-turn-on-red rule.
Worked example
You approach a flashing red signal at an intersection. Rule of thumb: treat it as a stop sign - come to a full stop, yield to cross traffic and pedestrians, then proceed when clear. Do not treat it as a yield.