Each year, the City of Irvine receives many inquiries about installing stop signs as a way to reduce accidents and speeding. Research shows that other measures are often more effective than adding more stop signs. Our experience has shown that simply improving the intersection visibility is often more effective in reducing traffic accidents. Improving intersection sight visibility often reduces the need to install more restrictive intersection controls.
Advantages of Warranted Stop Signs
Stop signs that are warranted provide the following:
Assignment of right of way to drivers at an intersection
Improved safety at the intersection
Disadvantages of Unwarranted Stop Signs
Stop signs installed that are NOT warranted cause the following:
Reduce their effectiveness and are largely ignored by drivers
Unnecessarily increases fuel consumption and air and noise pollution
May actually cause an increase in potential accidents
The Federal Manual on Uniform Traffic Control Devices (MUTCD) dictates the size, shape and color of all traffic signs. This manual has guidelines for installing signs and thus creates uniformity from state to state.
The City of Irvine is required by State law to comply with the guidelines of the MUTCD with California Supplement. In addition, the City has adopted policies for the installation of stop signs. These policies identify specific traffic and pedestrian volumes, accident history, and any unusual conditions which must be present at the intersection before these traffic control devices may be installed.
Stop signs cause a substantial inconvenience to motorists and should be installed at an intersection only after a careful engineering evaluation of the existing conditions indicates that their installation is appropriate and warranted.
A STOP sign may meet warrants for an intersection if one or more of the following conditions exist:
Intersections of a minor street with a minor street where the application of the normal right-of-way rule is unduly hazardous, and the accident history justifies the placement of a stop sign
If the minor street's safe approach speed is less than 10 MPH
Other intersections where a combination of high speed, restricted view, and serious accidents history correctable by the installation of a STOP sign
In a case where two main highways intersect, the STOP sign should normally be posted on the street with the lesser flow of traffic. Traffic engineering studies may justify a decision for the installation of an all-way STOP sign on the major streets, which would create a three-way or four-way stop intersection.
An all-way STOP sign may meet warrants for an intersection if one or more of the following conditions exist:
Indicated by five or more reported accidents within a 12 month period of a type correctable by a multiway stop installation. Type of accidents correctable typically are right and left turn collisions and right angle collisions.
Minimum Traffic Volumes
- The total vehicular volume entering the intersection from all approaches must average at least 500 vehicles per hour for any 8 hours of an average day, and...
- The combined vehicular and pedestrian volume from the minor street or highway must average at least 200 units per hour for the same 8 hours, with an average delay to the minor street vehicular traffic of at least 30 seconds per vehicle during the maximum hour, but...
- When the 85th percentile approach speed exceeds 40 MPH, the minimum vehicular volume warrant is 70% of the above requirements.
Stop signs should not be viewed as a cure-all for solving all safety problems; however, when properly located, can be a useful traffic control device to enhance safety for all roadway users.
The City is committed to providing the safest, most efficient and advanced Transportation Circulation System available. If you have any community traffic concerns, questions, or suggestions, please call the Irvine Traffic Research and Control (ITRAC) Center