Traffic Signs, Signals, and Pavement Markings
Signs: read shape and color first
Every sign answers two questions: what kind of message is this (color and shape) and what exactly does it require (words and symbols). Regulatory signs - stop, yield, speed limit, one way, no turn - tell you what you must or must not do; they are usually white with black lettering, red with white, or black with white. Warning signs are yellow diamonds, with fluorescent yellow-green for school and pedestrian warnings. Construction and maintenance warnings are orange. Guide signs are green (destinations, exits) or blue (services), and brown signs mark recreation areas.
Shapes carry meaning on their own: octagon = stop, inverted triangle = yield, vertical rectangle = regulatory, diamond = warning, pennant = no-passing zone, round = railroad advance warning, and the X-shaped crossbuck marks the crossing itself. A five-sided pentagon signals a school zone or school crossing.
Signals
A steady red means stop and stay stopped until green. After a full stop you may turn right unless a sign prohibits it, and in Michigan you may turn left from a one-way street onto another one-way street after stopping. Flashing red works like a stop sign; flashing yellow means slow down and proceed with caution - it never means stop. A steady yellow warns the light is changing: stop if you can do so safely. A green arrow protects that movement; a green light means proceed only when the intersection is clear.
Pavement markings
Yellow lines separate traffic moving in opposite directions; white lines separate traffic moving the same way. Broken yellow allows passing when safe; double solid yellow forbids passing in both directions but still allows a left turn across it. Solid white lines mark the right edge or a lane you should not cross.
Rule of thumb: when a sign and a marking seem to conflict with your instinct, obey the most restrictive message, and treat any solid line as a wall.