Regulatory Signs
Regulatory signs tell you what you must do, must not do, or must qualify. In Alaska they follow the national pattern: white background, black legend, and often a red accent for prohibitions. The family includes STOP and YIELD, speed limits, lane-use controls, turn restrictions, one-way and do-not-enter signs, parking and stopping controls, and weight or size limits.
Know the mandatory meanings cold. A STOP sign requires a full stop at the stop line or, if none, at the crosswalk or the edge of the traveled way before entering. YIELD means slow, be ready to stop, and give the right of way to traffic on the intersecting road. DO NOT ENTER marks the wrong-way end of a one-way road; WRONG WAY reinforces it. A red circle with a slash means the action pictured is prohibited. Speed limit signs give the maximum legal speed in ideal conditions, not a target; Alaska's default urban limit is 25 mph and default rural limit is 55 mph unless posted otherwise, and questions often test that posted signs override defaults.
Traps: confusing YIELD with a rolling stop; assuming a green light or an all-way stop changes a regulatory sign's force; missing that a sign applies only during stated hours or to a stated class of vehicle; and treating an advisory speed plaque on a yellow warning sign as a legal maximum.
Rule of thumb: read the shape first, the color second, the words third. White and black (or red and white) rectangles and octagons are commands, not suggestions. When a sign's condition (time, day, vehicle type) is printed on it, that condition is part of the law.