Regulatory Signs: Commands, Prohibitions, and Permissions
Regulatory signs tell you what you must, must not, or may do. They are the traffic-law signs, and disobeying one is a violation, not just a suggestion. Most are white rectangles with black legends, but the family also includes red-and-white signs (STOP, YIELD, DO NOT ENTER, WRONG WAY), the black-and-white speed limit sign, and red-circle-and-slash prohibition symbols.
What you must recognize
- Mandatory commands: STOP (full stop behind the line or crosswalk), YIELD (slow, be ready to stop, give right-of-way), and directional mandates like mandatory turn lanes.
- Prohibitions: DO NOT ENTER, WRONG WAY, NO LEFT TURN, NO U-TURN, and the red circle with a diagonal slash over a maneuver.
- Permissions and limits: speed limits, MINIMUM speed limits (blue/white in some editions, but the word MINIMUM is the tell), lane-use signs, and parking/standing rules.
- Selective regulatory: signs that apply only to certain vehicles or times, such as truck routes or time-restricted parking.
Traps to watch for
Questions love to blur the line between regulatory and warning. A yellow diamond is a warning; a white rectangle is generally regulatory. Another classic trap: treating YIELD as "stop only if a car is coming from the left" - you yield to all traffic with the right-of-way, including pedestrians. Also watch for the difference between NO PARKING and NO STANDING: standing (waiting with a driver present) is a narrower restriction than parking.
Rule of thumb
If the sign uses the words MUST, NO, or ONLY, or shows a red circle-slash, treat it as regulatory and assume it is enforceable law. When a question offers "slow down and proceed with caution" for a STOP sign, that is the distractor - STOP means a complete halt.
Worked example: You approach a white rectangular sign reading NO RIGHT TURN ON RED. The correct action is to stop for the red light and wait for green before turning; the sign removes a permission you would otherwise have.