Traffic Control Devices
Stop SignsStop signs are installed according to the California Manual on Uniform Traffic Control Devices (CA-MUTCD) to assign right-of-way at an intersection, not to control speeding. According to the CA-MUTCD stop signs must meet certain sets of criteria, called warrants, so there is uniformity in their use around the nation. These warrants identify specific vehicle, bicycle, and pedestrian volumes, accident history, and any unusual conditions which must be present at the intersection for a stop sign to be installed.
Through StreetsThere are certain streets within the City of Santa Rosa, designated Through Streets by City Council resolution that cannot have stop signs. Most of these are arterial streets designed to maintain higher traffic volumes for the more efficient movement of vehicles throughout the City.
Engineering EvaluationAt intersections without stop controls the installation of two-way stop signs are done only after a thorough engineering evaluation based on the following criteria:
- Stopping the direction that conflicts the most with established pedestrian crossing activity or school walking routes.
- Stopping the direction that has the best sight distance to conflicting traffic.
- Stopping the direction that has the longest distance of uninterrupted flow approaching the intersection.
- Stopping the direction that has obscured vision, dips, or bumps that already require drivers to use lower operating speeds.
- Stopping through traffic at highway-railroad grade crossings without gates or flashing signals.
Intersection ExaminationLocations that currently have two-way stop control also have warrants for determining if the intersection would be better suited with all-way stop controls. Generally all-way stop controls are used when the vehicle volumes of the intersecting streets are approximately equal. Requests to review intersections for multi-way stop control are evaluated using the warrants established by the CA-MUTCD as follows:
Interim MeasureWhere traffic control signals are justified, the multi-way stop is an interim measure that can be installed quickly to control traffic while arrangements are being made for the installation of the traffic control signal.
CrashesA crash problem, as indicated by 5 or more reported crashes in a 12-month period that are susceptible to correction by a multi-way stop installation. Such crashes include right - and left-turn collisions as well as right-angle collisions.
Minimum VolumesThe vehicular volume entering the intersection from the major street approaches averages at least 300 vehicles per hour for any 8 hours of an average day, and the combined vehicular, pedestrian, and bicycle volume entering the intersection from the minor street approaches averages at least 200 units per hour for the same 8 hours, with an average delay to minor-street vehicular traffic of at least 30 seconds per vehicle during the highest hour.
Posted Speed LimitIf posted speed of the major-street traffic exceeds 40 miles per hour the minimum vehicular volume warrants are 70% of the above values.
Multiple WarrantsWhere no single warrant is satisfied, but where crash and volume warrants are all satisfied to 80% of the minimum values, a multi-way stop control may also be considered.
If there is an intersection that you think we should investigate for the installation of stop signs please contact Traffic Engineering at 707-543-3814.