Pavement Markings and Sign Colors/Shapes
Pavement Markings and Sign Colors/Shapes
Markings and sign colors form a language. The Guam exam tests whether you can separate opposing traffic from same-direction traffic, read passing zones, and identify a sign by shape alone.
Core rules
- Yellow lines separate traffic moving in opposite directions. White lines separate lanes moving in the same direction or mark edges.
- Broken yellow center line: passing allowed when safe. Solid yellow: no passing. Double yellow with one solid and one broken: passing allowed only on the side with the broken line.
- A solid white edge line marks the right edge; a solid white lane line discourages lane changes; broken white allows changes.
- Stop bar: a wide white line before a crosswalk or intersection. Crosswalk markings: white parallel bars or a ladder pattern.
- Shapes: octagon = STOP; downward triangle = YIELD; pentagon = school; circle = railroad advance warning; diamond = warning; rectangle = regulatory or guide.
- Colors: red = prohibition/stop/yield; yellow = warning; orange = work zone; green = guide; blue = services; brown = recreation; fluorescent yellow-green = school/pedestrian; white = regulatory/guide.
Worked example
You are on a two-lane road with a double yellow center line. Your side is solid; the opposing side is broken. A slow truck ahead is doing 25 mph in a 45 mph zone. You may not pass, because the broken line belongs to the opposing traffic side; it permits oncoming drivers to pass, not you. Wait until your side has a broken yellow line and you can see enough clear road to complete the pass safely. The solid white edge line on your right is not a passing lane; it marks the edge of the travelway.
Traps
Do not assume yellow always means no passing: a broken yellow line allows passing when safe. Do not use a white lane line to judge opposing traffic; white separates same-direction lanes or edges. Do not memorize colors without shapes: a yellow diamond warns, while an orange diamond marks a work zone. Do not cross a solid white edge line to pass; use it only for a turn or to reach a shoulder when permitted.