Stop Signs: Requirements and Uses

The stop sign was designed to make drivers aware that they must come to a complete stop and make sure the intersection is clear of vehicles and pedestrians before proceeding. 

Main uses of stop signs include:

  • To assign right-of-way at an intersection

  • To prevent crashes in areas with high traffic flow and volume (if it's an area with a very high rate, a traffic light may be more effective) 

  • To ensure traffic flows smoothly and predictably

  • In areas where sight distances approaching the intersection are substandard and approaching traffic would run a strong risk of being involved in collisions

  • On a street leading into a through street or highway 

  • Places with high frequencies of car crashes 

Stop signs are considered a regulatory sign because they give notice of traffic laws or regulations. Regulatory signs need to be retroreflective or illuminated to show the same shape and similar color both by day and night. High Intensity Prismatic (link to vinyl) and Diamond Grade reflective materials meet the standard reflectivity requirement for stop signs because of their retroreflective properties.

Stop Sign Requirements

There are also specific requirements in regards to the size of a stop sign and where it is being installed. The size requirements are as follows:

  • 18” stop signs can be found on bikeways and shared-use pathways

  • 24” stop signs are used primarily in parking lots and on private roads

  • 30” stop signs are the minimum size requirement for official roadways and are required for single and conventional roadways

  • 36” stop signs are required when in place at a multi-lane approach, for dangerous intersections, and on expressways

  • 48” stop signs are used in situations that require an “over sized” stop sign where speed, volume, or other factors require the need for increased visibility

All-way and 4-way signs are often purchased along with stop signs in areas where there are safety concerns associated with pedestrians, bicyclists, and all road users expecting other road users to stop. Often found at intersections or where a road doesn't have a traffic light, stop signs are one of the most important and significant road traffic signs there is. 

Important Stop Sign LINKS


Intersection Safety Issue Briefs STOP 

Minimum Sign Retroreflectivity Requirements