Traffic Calming

Neighborhood Traffic Calming Program

City of Lynnwood has a mature and successful Neighborhood Traffic Calming Program.

The purpose of the City of Lynnwood Neighborhood Traffic Calming Program is to provide a consistent, data-driven, and equitable process for addressing speeding concerns on public streets. The program seeks to balance neighborhood concerns, improve mobility, emergency response needs, and overall livability.

If you would like to report a speeding concern, please review the following information before contacting City staff. In many cases, what may appear to be a speeding issue is within established state and national guidelines.

Speed limits and traffic conditions are evaluated using industry-standard engineering practices. Under Washington State law and guidance, a key factor in determining appropriate speed limits is the 85th percentile speed—that is, the speed at or below which 85 out of 100 motorists are traveling under free-flowing conditions. This methodology reflects the behavior of most drivers and is widely used to promote safe and reasonable speed zoning.

As a result, it is expected that approximately 15% of motorists may exceed the posted speed limit, and a roadway may still be operating within acceptable safety standards.

The use of the 85th percentile speed is supported through the adoption of the Manual on Uniform Traffic Control Devices (MUTCD) by Washington State, as codified in WAC 468-95-010, which establishes standards for traffic control devices and engineering practices. Additionally, RCW 46.61.400 (Basic Rule Law) requires drivers to operate vehicles at speeds that are reasonable and prudent under the conditions, regardless of posted limits.

If you notice an occasional vehicle exceeding the speed limit, there is a high likelihood that there is not a speeding issue occurring. If on the other hand, a significant number of vehicles are exceeding the speed limit, there may be a valid speeding issue occurring. If this is the case, feel free to contact the Traffic Department at 425-670-5236 or pwrequest@LynnwoodWA.gov. Please include the following information:

Your Name
Your email (preferred) or phone number
The street you are concerned about and closest side streets
Also, any other information you can provide like time of day, direction of travel…

Requesting Speed Bumps

The installation of speed bumps is one of the most frequently requested traffic calming measures, particularly in residential neighborhoods where children may play in or near the street. While these concerns are understandable, it is important to recognize that speed bumps are not automatically installed upon request. Public streets are designed to serve a variety of road users, including motorists, pedestrians, cyclists, and emergency responders, and must balance safety, mobility, and accessibility for all.

Before contacting the City or submitting a formal request, residents should be aware that traffic studies conducted by the City of Lynnwood Traffic Department often determine that traffic calming measures, including speed bumps, are not warranted. These determinations are based on established engineering standards and guidelines, which evaluate factors such as vehicle speeds, traffic volumes, roadway design, and safety history.

As outlined previously, many streets operate within acceptable speed thresholds under state and national criteria, even when some motorists exceed posted limits. For this reason, requests for speed bumps must meet specific eligibility requirements supported by data collected through formal traffic studies.

Residents are encouraged to consider these factors prior to submitting a request and to provide detailed information if they believe a location may qualify for further evaluation.

Questions? Contact the Traffic Department at 425-670-5236 or pwrequest@LynnwoodWA.gov