Road Signs, Signals, and Pavement Markings
Read the shape first
Octagon = stop. Inverted triangle = yield. Diamond = warning. Pennant = no-passing zone. Round = railroad advance warning. Five-sided = school zone. Rectangle = regulatory (rules) or guide (directions). Colors carry meaning too: red for stop or prohibition, yellow for warning, orange for construction and maintenance, green for guidance and destinations, blue for services, brown for recreation, and fluorescent yellow-green for pedestrians and bicycles.
Signals
A steady red means stop and stay stopped until green, though right on red is permitted after a stop unless posted. A red arrow forbids that movement - you may not turn on a red arrow. A flashing red is a stop sign: stop, then proceed when clear. A flashing yellow means slow down and proceed with caution; you do not have to stop. A green light means go only if the intersection is clear - it never grants an absolute right of way. A yellow light means stop if you can do so safely.
Pavement markings
Yellow lines separate traffic moving in opposite directions; white lines separate traffic moving the same way or mark the road edge. A broken yellow line means you may pass when safe; a double solid yellow line means no passing in either direction. Where one line is solid and the other broken, pass only if the broken line is on your side. A wide white bar is the stop line; white parallel bars mark a crosswalk; a diamond symbol marks an HOV lane.
Rule of thumb: The word "flashing" overrides the color association - flashing red acts like a stop sign, flashing yellow is only a warning. For lines, ask which line is on your side; that one governs you.