Traffic Signs, Signals, and Road Markings
Read the road in three layers
Signs and pavement markings tell you what the law requires; signals tell you who moves next. Study every device in the same order: shape, then color, then message.
Shapes. Octagon = STOP. Inverted triangle = YIELD. Diamond = warning (hazard ahead). Vertical rectangle = regulatory (rules you must obey). Horizontal rectangle = guide (directions, distances). Pentagon = school zone. Round = railroad advance warning. Crossbuck = the railroad crossing itself.
Colors. Red = stop or prohibit. Yellow = warning. Fluorescent yellow-green = school and pedestrian. Orange = work zone. White = regulatory. Green = guide and distance. Blue = services. Brown = recreation and points of interest.
Signals. A steady red means stop and stay stopped. Flashing red means stop, then proceed when clear. Flashing yellow means slow down and proceed with caution. A green arrow protects that movement; the yellow arrow warns the protected movement is ending, so do not enter the intersection on it.
Markings. Yellow lines separate traffic moving in opposite directions; white lines separate lanes moving the same way. Double solid yellow means no passing in either direction. A broken yellow line on your side allows passing when safe. Wide white bars mark crosswalks, and a solid white line across your lane is the stop bar.
Traps. Confusing a flashing yellow signal with a stale green light; treating a two-way left-turn lane as a travel or passing lane; and forgetting that signs outrank pavement markings, while a police officer directing traffic outranks both.
Rule of thumb. Shape first, color second, words last. If you can name the shape and color before you can read the sign, you already know how to react.