Regulatory Signs
Regulatory signs are the traffic-law signs: they tell you what you must do or must not do, and disobeying one is a violation, not just a bad idea. The Pennsylvania exam tests whether you can recognize them by shape, color, and message, and whether you know where the legal action begins.
Core rules
- Most regulatory signs are vertical white rectangles with black legends and symbols.
- Exceptions you must know: STOP is a red octagon; YIELD is a red-and-white inverted triangle; DO NOT ENTER is a red square with a white horizontal bar.
- STOP means a complete cessation of movement at the stop line, at the marked crosswalk if there is no line, or at the edge of the intersection if neither exists. Then yield to pedestrians and cross traffic.
- YIELD means slow down and give the right of way; stop only if traffic requires it.
- A posted SPEED LIMIT is the legal maximum under favorable conditions, not a target or a minimum.
- Turn, lane-use, weight, and height restrictions are regulatory even when they appear on a small supplemental plaque.
Worked example
You reach an intersection and see a white rectangular sign reading NO RIGHT TURN, with a smaller plaque reading 7-9 AM MON-FRI. The sign is regulatory and the plaque limits its legal effect to those hours and days. Outside that window, a right turn is permitted unless another sign or the signal prohibits it. The reasoning: read the main sign for the rule, then the plaque for when the rule applies.
Traps
Do not confuse a white SPEED LIMIT sign with a yellow advisory-speed plaque under a warning sign; the yellow plaque is advice, not a legal limit. At a stop, the stop line comes before the crosswalk, so stopping on the crosswalk is a common error. NO TURN ON RED is a regulatory sign that overrides the general right-on-red permission.