The City receives many inquiries regarding the application of various traffic control devices, and installation of stop signs is one of the most common requests. If stop signs were installed at every requested location, there would be a stop sign at nearly every intersection. This would cause intense congestion and more delay in your everyday travels, create more pollution, and reduce safety. Therefore, criteria have been developed to determine where stop signs can be beneficial, and where they are not.
A great deal of study has been performed on stop signs, and their effects and side-effects are well known. Studies have been performed since at least the 1950s by university researchers, federal, state, and local government agencies, the insurance industry, and professional associations. These studies have evaluated the effect of stop signs on safety, the environment, the economy, quality of life, and more. Fortunately, all of this study and knowledge has been compiled and considered in the guidelines established in a single source for the entire country, the Manual for Uniform Traffic Control Devices (MUTCD).
The MUTCD determines the size, shape, color, and use of all traffic signs. The manual has criteria for installing signs and thus creates uniformity from state to state identifying specific traffic, bicycle and pedestrian volumes, accident history, and any unusual conditions, which must be present at an intersection, before these traffic control devices may be installed. These warrants are based on the massive amount of research that has been performed nationwide and published over at least seven decades.
One of the most common reasons for requesting stop signs is to reduce speeding. Unfortunately, stop signs have proven to be ineffective for this purpose. A driver who is willingly violating the speed limit and its signs, should not be expected to obey a stop sign. In fact, some drivers will actually increase their speed after the stop sign to make up for the lost time. The wealth of knowledge about the effectiveness of stop signs indicates that they are effective in assigning right-of-way at an intersection, not controlling speeding.
The criteria for installation of stop signs at one or two legs of an intersection are quoted from the MUTCD below. While the criteria are complex, this highlights the amount of thought and effort that has been invested in developing good safe guidelines for installation of stop signs.
YIELD or STOP signs should be used at an intersection if one or more of the following conditions exist:
- An intersection of a less important road with a main road where application of the normal right-of-way rule would not be expected to provide reasonable compliance with the law;
- A street entering a designated through highway or street; and/or
- An unsignalized intersection in a signalized area.
In addition, the use of YIELD or STOP signs should be considered at the intersection of two minor streets or local roads where the intersection has more than three approaches and where one or more of the following conditions exist:
- The combined vehicular, bicycle, and pedestrian volume entering the intersection from all approaches averages more than 2,000 units per day;
- The ability to see conflicting traffic on an approach is not sufficient to allow a road user to stop or yield in compliance with the normal right-of-way rule if such stopping or yielding is necessary; and/or
- Crash records indicate that five or more crashes that involve the failure to yield the right-of-way at the intersection under the normal right-of-way rule have been reported within a 3-year period, or that three or more such crashes have been reported within a 2-year period.
YIELD or STOP signs should not be used for speed control.
The criteria for installation of stop signs on all legs of an intersection are quoted from the MUTCD below:
Multi-way stop control can be useful as a safety measure at intersections if certain traffic conditions exist. Safety concerns associated with multi-way stops include pedestrians, bicyclists, and all road users expecting other road users to stop. Multi-way stop control is used where the volume of traffic on the intersecting roads is approximately equal.
The restrictions on the use of STOP signs described in Section 2B.04 also apply to multi-way stop applications.
The decision to install multi-way stop control should be based on an engineering study.
The following criteria should be considered in the engineering study for a multi-way STOP sign installation:
- Where 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.
- Five or more reported crashes in a 12-month period that are susceptible to correction by a multi-way stop installation. Such crashes include right-turn and left-turn collisions as well as right-angle collisions.
- Minimum volumes:
- The vehicular volume entering the intersection from the major street approaches (total of both 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 (total of both 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; but
- If the 85th-percentile approach speed of the major-street traffic exceeds 40 mph, the minimum vehicular volume warrants are 70 percent of the values provided in Items 1 and 2.
- Where no single criterion is satisfied, but where Criteria B, C.1, and C.2 are all satisfied to 80 percent of the minimum values. Criterion C.3 is excluded from this condition.
The California MUTCD chapter that addresses stop signs can be found at MUTCD Stop Sign Criteria