Signs, Signals, and Road Markings
Read the shape first, then the color
Signs are designed so you can identify them before you can read them. A red octagon means STOP; an inverted red-and-white triangle means YIELD; a yellow diamond is a warning; an orange diamond or rectangle is a work zone; a fluorescent yellow-green diamond flags schools, pedestrians, or bicycles; a white rectangle is regulatory (speed limits, lane use, turn rules); green rectangles guide you to destinations; blue is services; brown is recreation and parks. A round yellow sign warns that a railroad crossing is ahead, while a white X-shaped crossbuck marks the crossing itself.
Signals
A solid red means stop and stay stopped. A red arrow means no movement in that direction. A flashing red is the same as a stop sign: stop, then go when it is safe. A solid yellow means the light is about to turn red - stop if you can do so safely; it is never an instruction to speed up. A flashing yellow means proceed with caution, and a flashing yellow arrow means your turn is unprotected, so yield to oncoming traffic. A green arrow is a protected movement; a solid green means go when the intersection is clear, yielding to pedestrians and to vehicles still clearing the box.
Pavement markings
Yellow lines separate traffic moving in opposite directions; white lines separate traffic moving the same way. A broken yellow line allows passing when safe; solid or double solid yellow forbids it. White edge lines mark the right edge of the road, and a solid white line beside your lane discourages or prohibits lane changes. Stop lines show where to stop at signals and stop signs.
Trap: test questions love the flashing yellow arrow (unprotected turn, not a free pass) and the yellow light that 'means hurry.' Rule of thumb: yellow warns, red commands, white separates same-direction traffic.