Road signs

Regulatory Signs

Signs that tell you what you must or must not do.

Regulatory signs are rectangular or square, most often white with black lettering, and use a green circle for a permitted action or a red circle with a diagonal line for a prohibited one.

Regulatory signs set enforceable rules. A driver who ignores one is not just missing information, they are breaking a rule the sign states outright.

Key facts

Regulatory signs are typically rectangular or square, unlike the diamond of a warning sign or the octagon of a stop sign.
A green circle symbol means the shown action is permitted; a red circle with a diagonal slash through it means the shown action is prohibited.

Identify the rule being stated

A regulatory sign states a speed limit, a turn restriction, a one-way direction, a no-passing zone, or a similar enforceable rule. Unlike a warning sign, which describes a hazard, a regulatory sign describes an obligation.

Some regulatory signs use words alone ("No Parking"), others use only a symbol, and many combine both: read the whole sign rather than reacting to the symbol shape alone.

Read arrows, times, and exceptions

An arrow on a regulatory sign narrows the rule to a specific direction or lane: a no-left-turn sign with an arrow applies only to the movement the arrow shows. A posted time range (for example, a restriction that applies only during school hours or rush hour) means the rule does not apply outside that window.

Watch for a smaller tab below the main sign; it often adds an exception, such as "except buses" or a distance over which the rule applies, and changes whether the rule affects your specific situation.

Confirm the sign applies to you

A regulatory sign can be posted for one lane, one direction of travel, or one side of a divided road. Before acting on it, confirm it governs your lane and direction, since an adjacent lane can be under a different rule.

A regulatory sign is a legal instruction, not a suggestion: treating one as optional because traffic looks light is a common and cited driving error.

Common mistakes

Treating a posted turn restriction as advisory rather than mandatory.
Missing a time-of-day tab and assuming a restriction always applies, or never applies.
Confusing a regulatory sign’s rectangular shape with an information sign because both can be white or green.
Acting on a sign posted for a different lane than the one you are in.