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What color and shape are regulatory signs *?

Regulatory signs play a crucial role in traffic safety by informing drivers of traffic laws, regulations, and requirements. Understanding the colors and shapes of these signs allows drivers to quickly recognize and comply with posted regulations. This article will provide a comprehensive overview of regulatory sign color and shape requirements in the United States.

Regulatory signs are rectangular-shaped signs that inform road users of selected traffic laws or regulations and indicate the applicability of legal requirements that would not otherwise be apparent. They are designed and used to guide, warn, and regulate traffic.

The Manual on Uniform Traffic Control Devices (MUTCD) published by the Federal Highway Administration (FHWA) provides national standards for all pavement markings, highway signs, and traffic signals in the United States. To promote highway safety and efficiency by providing for the orderly movement of road users on streets and highways, the MUTCD specifies sign sizes, shapes, colors, fonts, placement and other criteria for regulatory signs.

Regulatory Sign Colors

The MUTCD dictates the following color requirements for regulatory sign backgrounds:

  • Red – Used for signs conveying stop, yield, do not enter, wrong way, or prohibition messages.
  • White – Used for signs conveying parking regulations and restrictions.
  • Green – Used for signs conveying guidance, direction, destinations, distances, services, and recreational or cultural interest.
  • Blue – Used for signs conveying services, motorist services guidance, and evacuation route information.
  • Yellow – Used for warning signs conveying general warning messages.
  • Orange – Used for warning signs conveying temporary traffic control warning messages.
  • Brown – Used for signs to parks, recreational, and cultural interest areas.
  • Black – Used for symbols, arrows, letters, and borders on white and yellow sign backgrounds.

Additionally, fluorescent yellow-green backgrounds may be used for school warning signs. Black legends are typically used with all background colors except for red. Red legends are used with red backgrounds.

Regulatory Sign Shapes

Regulatory signs have standard distinctive shapes that correspond to their functions. The MUTCD specifies the following standardized shapes:

Sign Shape Regulatory Message Conveyed
Octagon Stop
Equilateral triangle (point down) Yield
Rectangle (horizontal) Traffic regulation, restriction, or prohibition
Pennant No passing zone
Pentagon School advance warning sign
Crossbuck Grade crossing advance warning
Diamond Warning
Rectangle (vertical) Temporary traffic control

Some common regulatory sign examples include:

  • STOP – Octagonal with white letters on red background
  • YIELD – Red and white upward pointing triangle
  • DO NOT ENTER – White letters on red background
  • WRONG WAY – White legend on red background
  • SPEED LIMIT – Black numbers on white rectangular background
  • NO U-TURN – Black letters and arrow on white background

Right-of-Way Signs

Right-of-way regulatory signs establish the right-of-way rule at intersections and other roadway junctions where drivers need to know who has the right-of-way. They are generally rectangular in shape with a white legend on a red background. Some common examples include:

Sign Description
STOP Come to a complete stop and yield right-of-way to cross traffic and pedestrians before proceeding
YIELD Slow down to yield the right-of-way to cross vehicular and pedestrian traffic
ALL WAY Traffic from all directions must stop

Prohibitory Signs

Prohibitory signs indicate certain types of vehicles, maneuvers, or actions that are not permitted. They have a black symbol or message on a white background with a red circle and slash. Some common prohibitory regulatory sign examples include:

Sign Prohibition
NO LEFT TURN Left turns not allowed
NO U TURN U-turns not allowed
NO TRUCKS Trucks excluded from roadway or section of roadway
NO BICYCLES Bicyclists prohibited from roadway or facility

Permissive Signs

Permissive signs convey permitted actions that are not mandatory. They often establish conditional requirements for certain maneuvers to improve safety and operations. Typical permissive regulatory signs include:

Sign Permission Granted
RIGHT TURN ON RED AFTER STOP Right turn allowed after coming to complete stop
LEFT ON GREEN ARROW ONLY Left turn only allowed when green arrow signal displayed
U-TURN YIELD TO RIGHT TURN U-turn permitted after yielding to right-turning vehicles

Parking and Standing Signs

Parking and standing regulatory signs convey parking restrictions and prohibitions. They use white legends on rectangular blue or red backgrounds. Some examples include:

Sign Parking Rule
NO PARKING Parking prohibited at all times
NO PARKING ON PAVEMENT Parking prohibited on paved portion of roadway
2 HOUR PARKING 8 AM – 6 PM 2 hour parking limit between 8am-6pm

Speed Limit Signs

Speed limit signs inform drivers of the maximum legal speed they are permitted to travel on that section of roadway. They have black numerals on a white rectangular background. Some examples include:

Sign Speed Limit
SPEED LIMIT 55 Maximum speed 55 mph
TRUCKS SPEED LIMIT 45 Maximum truck speed 45 mph
NIGHT SPEED LIMIT 40 Nighttime speed limit 40 mph

Movement Prohibition Signs

Movement prohibition signs restrict certain movements at intersections or other roadway junctions. They have white arrow symbols on rectangular red backgrounds. Some examples are:

Sign Movement Restriction
NO LEFT TURN Left turns prohibited
NO STRAIGHT THROUGH Straight through movement prohibited
NO U-TURN U-turns prohibited

Lane Use Control Signs

Lane use signs regulate the direction or type of traffic allowed to use designated lanes. They have white symbols or messages on black backgrounds. Some examples are:

Sign Lane Use Restriction
RIGHT LANE MUST TURN RIGHT Traffic in right lane must turn right
CENTER LANE ONLY Only traffic in center lane permitted
TRANSIT LANE Lane reserved for transit vehicles


Understanding regulatory traffic sign colors and shapes is critical for road users. Red signs convey stop, yield, restriction, and prohibition messages. Circular and triangular shapes assign right-of-way. White, black, and blue signs convey parking rules, speed limits, and guidances. Distinct colors and standardized shapes allow regulatory signs to be identified and understood quickly to improve compliance and roadway safety.