Traffic signs, signals, and road markings
Signs by shape and color
Maine uses standard shapes and colors to make signs readable at a glance. An octagon is STOP; an inverted triangle is YIELD; a pennant marks a no-passing zone; a diamond warns of a hazard; a pentagon marks a school zone or school crossing; a round sign warns of a railroad crossing. Red means stop or prohibition, yellow warns, orange marks work zones, green gives direction or distance, blue gives service information, and brown marks recreation or cultural sites. Regulatory signs-speed limits, lane-use arrows, no-turn signs-must be obeyed. Warning signs tell you to adjust speed or position, not to stop automatically.
Signals and markings
A steady red means stop; after stopping, you may turn right on red in Maine unless a sign forbids it, yielding to traffic and pedestrians. A steady yellow means the light is changing: stop if you can do so safely. A green light lets you proceed when clear, but does not protect you from cross traffic making a legal turn. A flashing red is treated as a stop sign; a flashing yellow means slow down and proceed with caution. Solid yellow center lines separate opposite directions and mean no passing when solid on your side. Broken yellow allows passing when safe. White lines separate traffic moving the same direction; solid white edge lines mark the roadway edge.
Worked example
You approach an intersection with a flashing red light and a crosswalk. Treat it as a stop sign: stop completely, check the crosswalk, then yield to cross traffic before proceeding. A green light at the same intersection would not let you ignore a pedestrian still in the crosswalk.
Traps
Yellow does not mean accelerate. A green arrow protects only the movement it shows. Do not cross a solid yellow line to pass, and do not treat a broken white line as permission to ignore lane boundaries.