Regulatory Signs
Regulatory signs are the law written on metal: they set speed limits, assign right-of-way, restrict turns and parking, and define lane use. The DC Road Signs Practice exam tests whether you can read these signs precisely - including the small supplementary plaques and arrows that change when and where a rule applies - and whether you know the legal consequence of ignoring one. A regulatory sign is not advice; failing to obey it is a moving or standing violation.
How regulatory signs work
Most regulatory signs are white rectangles with black legends, with red reserved for prohibitions such as STOP, YIELD, DO NOT ENTER and NO TURN ON RED. A restriction begins at the sign and continues until another sign cancels it, you pass an intersection, or the block ends. Arrows on parking signs point the direction the rule covers; a sign with a left-pointing arrow applies to the curb behind it.
The stop-and-yield family
At a STOP sign, come to a complete stop at the stop line. If there is no line, stop before the crosswalk; if there is no crosswalk, stop before the edge of the traveled way so you can see approaching traffic. At a YIELD sign, slow down and be ready to stop; you do not have to stop if the way is clearly clear. Right turn on red is permitted after a full stop and a yield to pedestrians and cross traffic unless a NO TURN ON RED sign is posted - a common restriction in downtown DC and near schools.
Parking restrictions
NO STOPPING means you may not halt at all, even briefly. NO STANDING lets you stop only long enough to pick up or drop off a passenger. NO PARKING lets you stop temporarily to load or unload but not leave the vehicle. Time limits, 'Except' plates and meter hours all modify the rule.
Worked example
A driver reaches a red light at an intersection with a NO TURN ON RED sign and a right-turn arrow that is not illuminated. The driver wants to turn right. Correct action: remain stopped until the signal gives a green arrow or green light. The posted sign removes the general right-turn-on-red permission; the arrow shows the only protected phase in which the turn is allowed.
Traps that cost marks
Reading a parking sign as covering the whole block when an arrow limits it; confusing NO STANDING with NO PARKING; rolling through a stop line into the crosswalk; and assuming a right turn on red is always legal. Also watch for 'EXCEPT' plates that exempt buses, permit holders or certain hours.