Traffic control devices
We follow the Manual on Uniform Traffic Control Devices (MUTCD) for the design and use of traffic control devices. This is the same manual used by other local cities and counties. Using the same manual makes it easier for travelers to understand what is expected.
"Children at Play" signs
We do not install "Children at Play" signs on County roads. The sign is not recognized by the MUTCD or local policy. There is no evidence that the sign slows traffic down or makes drivers more aware of children. The sign can also give a false sense of security to children and caregivers.
Guide signs direct travelers to some by the best route. It is not feasible to install signs listing all the possible destinations. These signs need to be simple and easy to see. The number of destinations should be kept to three or fewer.
These signals give visual and audio signals when there is time for you to cross a road. This helps ensure other traffic stops for pedestrians. Pedestrian signals may or may not have buttons to call the signal.
Pedestrian signals may have lights with the words WALK and DON'T WALK, or the lights with symbols of a walking person and an upraised hand.
A steady WALK or symbol of a walking person means that you may cross the road direction of the signal.
A flashing DON'T WALK or symbol of an upraised hand means that you should not start to cross the road, but a person who is already crossing should continue across.
A steady DON'T WALK or symbol of an upraised hand means that you cannot legally cross the road in that direction.
Pedestrian signals give you right-of-way to cross the road, but they do not guarantee safety. You must use good judgment when crossing a road. The following suggestions are offered in the interest of safety:
- Before crossing a signalized intersection, always push the pedestrian detector if one is present. This will guarantee adequate crossing time.
- If no pedestrian signal is present, cross as soon as the vehicle signal turns green for the direction you plan to cross.
Roundabouts and Bicycles
Cyclists have a legal right to ride in on the road with motor vehicle traffic when traveling through a roundabout, just like other intersections. This is true even if no “Bikes on road” sign is posted.
We use traffic studies to ensure that a traffic signal will improve safety for all travelers. These conditions, or warrants, can include the amount and type of traffic using the roads, school crossings, crash history, and more. We use standard traffic signal warrants developed by the Federal Highway Administration (FHWA).
The cost to design and install a traffic signal is depends on how complex the intersection is. Traffic signal projects are usually paid for as part of a road construction project or through private development.
Traffic signals can:
- Create orderly movement of traffic
- Increase capacity of the intersection
- Reduce frequency and severity of some of crashes, especially right-angle collisions
- Create protected crossing opportunities for bicyclists and pedestrians
Traffic signals may:
- Not prevent all types crashes
- Increase rear-end collisions
- Create a false sense of security, particularly for pedestrians
- Increase cut-through traffic in nearby neighborhoods
- Create unnecessary delays at certain times
- Increases air pollution from idling vehicles
- Lead to red-light running if travelers don’t feel the stop is needed
Bicycle Detection at Traffic Signals
Traffic signals can detect cyclists with either detection cameras or loops.
Detection cameras scan the road to see if bicycles and vehicles are waiting for the signal. A computer program adds time to the green signal to give cyclists more time to cross the road.
Detection loops are electrically charged wires in the pavement. The traffic signal is called when metal of bicycles and other vehicles interrupts the electric current.
The best place to wait for the signal depends on the shape of the loop:
- Diamond: Inside one of the points
- Circle: A quarter from the side of the circle
- Rectangle: At the middle front
Report traffic signal problems by submitting a service request or calling 503-846-7950.
Lighting fixtures must meet current standards when they are installed. Streetlights are usually maintained by either Portland General Electric (PGE) or Washington County.
To report a street light problem complete the form on PGE's web site or call 800-544-1795.
The Oregon Department of Transportation (ODOT) sets the speed zones for all roads in Oregon.
Speed limits may be set as close to the speed below which 85% of the vehicles travel on a given road. This way of setting the speed limit helps people follow the posted speed because it seems reasonable.
Speed limits that seem too low invite violation even by responsible drivers. Posting proper speed limits smooths traffic flow and aids effective law enforcement.
Traffic studies, crash history and road conditions are also considered when setting speed limits.
Speed signs are typically installed every quarter- or half-mile, depending on the road type. 25 mph speed signs are installed at the entrances to subdivisions where the speed zone changes from a higher speed to the residential speed. It is not practical to install speed signs at the end of every residential street.