TRN-2.01 - Traffic Control Devices

ARC-TRN-2.01

WHEREAS, the City Council on July 25, 1990, passed Resolution No. 34755 adopting the Manual on Uniform Traffic Control Devices, published by the U.S. Department of Transportation, Federal Highway Administration, as an administrative rule in the City of Portland, and

WHEREAS, this Manual has been revised as of December 28, 2001, and

WHEREAS, the Oregon Transportation Commission adopted this revised Manual as of April 11, 2002, along with the March 2002 Edition of the Oregon Supplements to the Manual on Uniform Traffic Control Devices, and

WHEREAS, the Oregon Vehicle Code requires that "all traffic control devices placed in this state shall conform to specifications approved by the Commission" (810.200(2)c)), and

WHEREAS, stop signs are traffic control devices and the City Council on June 17, 1992 passed Resolution No. 35003 adopting criteria for the installation of stop signs on Portland city streets, and

WHEREAS, the Office of Transportation finds the criteria for the expanded use of stop signs has successfully provided for safer streets and more livable neighborhoods, and

WHEREAS, it is desirable to adopt guidelines that provide for the installation of traffic control devices on all streets within the City of Portland.

NOW, THEREFORE, BE IT RESOLVED THAT the Manual on Uniform Traffic Control Devices, Millennium Edition, and the Oregon Supplement to this Manual as adopted and revised periodically by the Oregon Transportation Commission, be adopted by the Council as administrative rules for the installation and maintenance of traffic control devises on all City streets, and

BE IT FURTHER RESOLVED THAT the City's criteria for the installation of stop signs be revised and adopted as shown in Exhibit 1.

STOP Sign Applications

Guidance:

STOP signs should be used if engineering judgment indicates that one or more of the following conditions exist:

A. 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;

B. Street entering a through highway or street;

C. Unsignalized intersection in a signalized area; and/or

D. High speeds, restricted view, or crash records indicate a need for control by the STOP sign. STOP signs should be installed when three or more crashes are reported over a three-year period. The crashes being of a type correctable by the use of STOP sign control.

E. In an area of local streets bounded by through streets where the majority of intersections are controlled by STOP control, all of the remaining uncontrolled intersections may be considered for STOP control as a part of a comprehensive, area-wide “Neighborhood Stop Plan”.

Standard:

Because the potential for conflicting commands could create driver confusion, STOP signs shall not be installed at intersections where traffic control signals are installed and operating.

Portable or part-time STOP signs shall not be used except for emergency and temporary traffic control zone purposes.

Guidance:

STOP signs should not be used for speed control.

STOP signs should be installed in a manner that minimizes the numbers of vehicles having to stop. At intersections where a full stop is not necessary at all times, consideration should be given to using less restrictive measures such as YIELD signs.

Once the decision has been made to install two-way stop control, the decision regarding the appropriate street to stop should be based on engineering judgment. In most cases, the street carrying the lowest volume of traffic should be stopped.

A STOP sign should not be installed on the major street unless justified by a traffic engineering study.

Support:

The following are considerations that might influence the decision regarding the appropriate street upon which to install a STOP sign where two streets with relatively equal volumes and/or characteristics intersect:

A. Stopping the direction that conflicts the most with established pedestrian crossing activity or school walking routes;

B. Stopping the direction that has obscured vision, dips, or bumps that already require drivers to use lower operating speeds;

C. Stopping the direction that has the longest distance of uninterrupted flow approaching the intersection; and

D. Stopping the direction that has the best sight distance to conflicting traffic.

Multiway Stop Applications

Support:

Multiway stop control can be useful as a safety measure at intersections if certain traffic conditions exist. Safety concerns associated with multiway stops include pedestrians, bicyclists, and all road users expecting other road users to stop. Multiway stop control is used where the volume of traffic on the intersection roads is approximately equal.

Guidance:

The decision to install multiway stop control should be based on an engineering study.

The following criteria should be considered in the engineering study for a multiway STOP sign installation:

A. Where traffic control signals are justified, the multiway 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.

B. A crash problem, as indicated by the following:

1. On through streets a crash history for a two-year period indicates a rate of at least 1.5 crashes per million entering vehicles, the crashes being of the type correctable by all-way stop control, or

2. On local streets where the crash history indicates five or more reported crashes in a two-year period, the crashes being of the type correctable by all-way stop control

C. Minimum volumes:

1. 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

2. 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

3. If the 85th-percentile approach speed of the major-street traffic exceeds 65 km/h (40 mph), the minimum vehicular volume warrants are 70 percent of the above values.

D. 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.

Option:

Other criteria that may be considered in an engineering study include:

A. The need to control left-turn conflicts;

B. The need to control vehicle/pedestrian conflicts near locations that generate high pedestrian volumes;

C. Locations where a road user, after stopping, cannot see conflicting traffic and is not able to safely negotiate the intersection unless conflicting cross traffic is also required to stop; and

D. An intersection of two residential neighborhood collector (through) streets of similar design and operating characteristics where multiway stop control would improve traffic operational characteristics of the intersection.

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Resolution No. 36107.
Adopted by Council November 13, 2002. Effective November 13, 2002.