Neighborhood Traffic Operations: Traffic Calming Program
Under both state law and the Seattle Municipal Code, the speed limit on our non-arterial streets is 25 mph. Addressing community concerns when large numbers of drivers routinely travel much faster than the speed limit requires active participation by residents, working in a strong partnership with SDOT. This is always done in a phased approach, starting with ensuring that SDOT and the community have a clear and common understanding of the nature of the concern. We work together to educate drivers that use the street, whether they live in your neighborhood or elsewhere, and direct enforcement where it will have the most benefit. Moving through the process, we might identify relatively simple measures, such as reconfiguring parking on your street, or develop feasible and fundable traffic calming projects that address your concern.
Please read through the following information, which provides an overview of the steps we’ll take in working with you, and let us know if you want to work with us to address speeding on your street.
Step 1 – Application
Concerned with speeding or volumes on your street? Then please fill out this online Resident Request Form.
Or you can call SDOT neighborhood Traffic Operations at (206) 684-0353. If you leave a message, please leave your phone number, email address and the street you are concerned about.
- Step 2 - Preliminary Assessment
SDOT staff will conduct a brief preliminary assessment and respond to you. If the preliminary assessment suggests that your street is suited for consideration under the traffic calming program, you will be provided with an enrollment form that begins your participation in the traffic calming program.
- Step 3 – Enrolling in the Traffic Calming Program
To ensure that there is broad community support for participating in the traffic calming program, we’ll ask that you enlist the support of at least four of your neighbors. Once you return the enrollment form with their signatures, we ask that at least one of you attend a Neighborhood Traffic Safety Meeting, which is held in the evening at alternating locations throughout the city. At the meeting, you will participate in a discussion of different traffic calming options, and you and/or your neighbors will be trained in the use of the radar speed gun.
- Step 4 – Neighborhood Speed Monitoring
Neighborhood Speed Monitoring is an important step in the educational and enforcement aspects of the traffic calming program. During this step, you will collect information, using a radar speed gun, about vehicle speeds on your street. This information serves as a good “snap shot” of how drivers are behaving as they travel through your neighborhood. We’ll also send letters to drivers that were measured as traveling faster than 30 mph.
- Step 5 – SDOT Review
Next, SDOT staff will compile the results of your radar speed gun data. We will calculate the “85th percentile speed”. This is the speed that 85% of drivers are traveling at or below, and is a good measure of overall driver compliance with the speed limit. We also review your data to determine approximate traffic volumes and direction of travel.
At this point, we’ll work with you on developing appropriate community-oriented traffic calming measures. These measures may consist of signs, parking management, and educational tools that encourage drivers on your street to slow down.
SDOT will conduct traffic studies to see if the measures implemented in Phase I were able to lower vehicle speeds. If speeds are still high, SDOT staff will work with your community in identifying which (if any) Physical Traffic Calming Measures may be effective at further reducing speeds. All physical traffic calming measures have advantages and disadvantages, but there may be measures that are suitable for use on your street.
Streets identified for potential traffic calming projects are prioritized based on speed, available funding and community support.
If speeds are not high enough to qualify for Phase II funding of traffic calming devices, SDOT may encourage you to apply for Alternative Funding.