Reducing Local Street Speed Limits in Bellevue: Safety Starts on Your Street – Part 1

Until recently, the default speed limit on City of Bellevue streets was 25 miles per hour (mph), unless otherwise posted. This applied to arterial streets (that ranged from 25-40 mph) and local streets (default 25 mph), which comprise approximately 64% of the streets in the city’s transportation network.

Last October, the Bellevue City Council unanimously approved ordinance 6809, lowering the default speed limit on all Bellevue streets to 20 mph, except where otherwise posted. In effect, this limits the speed on most local streets to 20 mph. This work, in support of Vision Zero and in response to concerns about speeding, was led by Bellevue’s Neighborhood Traffic Safety Services (NTSS) division within the Transportation Department.

In this blog series, we will detail Bellevue’s journey to lowering the speed limit on local streets. From why do it in the first place and how to approach outreach, to lessons learned that could help your agency consider a new approach to posting speed limits.

Leaning into Speed Limit Reviews

For nearly 40 years, the City of Bellevue has been a leader in neighborhood traffic calming. We work closely with residents to identify traffic safety concerns, evaluate them based on priority, and then deliver solutions to reduce speeds and volumes.

The main features of our traffic safety program have been education, encouragement, and engineering solutions. Since the adoption of Vision Zero and the Federal Highway Administration’s Safe Systems approach to meet the city’s goal to eliminate traffic deaths and serious-injury collisions on city streets by 2030, we have looked to build upon the success of the traffic calming program while also finding new approaches and avenues to advance traffic safety goals. This led to considering speed limit evaluations, particularly on local streets.

While the relationship between speed and safety outcomes is well-documented — lower speeds are proven to increase likelihood of crash survivability — the relationship between lower speed limits and reduced speeding is less understood. A Portland State University study showed a reduction in high-end speeding — the type of speeding of most concern — after a reduction in speed limits. However, we weren’t sure if we would see the same results in Bellevue. Over the course of three years, we tested 20-mph speed limits in several neighborhoods and confirmed high-end speeding reduction. The success we saw through the testing ultimately informed a larger, citywide change to speed limits on local streets.

Legal Authority and Community Needs

There are many reasons to consider evaluating — and perhaps, modifying — speed limits. When considering lower speed limits, consider your legal and policy support for beginning such a journey.

First, cities have authority from the state to reduce speed limits. RCW 46.61.415 allows local authorities to establish a maximum speed limit of 20 mph on a nonarterial roadway without going through an engineering and traffic investigation if the local authority has developed procedures regarding establishing a maximum speed limit under subsection(3)(a). Changing the speed limit in Bellevue is accomplished via amendments to Municipal Code Ch. 11.32. This code sets the speed limit for all public streets in Bellevue and must be modified each and every time a speed limit is changed.

With state and city code in place, we developed a Speed Limit Standard Operating Procedures (SOP) that articulates speed limit setting for both arterial and local streets. Beyond this framework, there is substantial policy and community support in Bellevue for lowering the speed limit. Some examples include:

• Comprehensive Plan: There are policies in the city’s Transportation Element to support lowering vehicle travel speeds along local streets along with developing a programmatic approach to Vision Zero.
• Vision Zero: In addition to comprehensive plan policies supporting Vision Zero, the city’s subsequent Vision Zero activities have laid the groundwork for employing the Safe Systems approach, developing annual Vision Zero Action Plans, and charting progress. Specifically, in recent years items within the action plan included advancing neighborhood pilots to lower the speed limit on neighborhood streets (see Action 6, 2022) and more broadly, including advancing “citywide efforts to implement a local street speed limit reduction policy reducing speed limits on local streets to 20 mph.” (see Action 6, 2024).
• Community Concerns: Speeding on local streets — as documented by resident interactions and logged in the transportation department’s customer tracking database — is far and away the most cited traffic safety concern heard from the community.

Testing the Idea in a Local Context - Neighborhood Pilots

With this considerable policy and administrative framework in place, we sought to 1) examine whether reducing the local street speed limit was effective in Bellevue, and 2) learn about how a local street speed limit reduction should be applied in a Bellevue context.

This was approached through three pilots that implemented 20-mph speed limits in three geographically diverse Bellevue neighborhoods (Surrey Downs, East Bellevue Greenway, Eastgate/Tyee) over three years. These deployments were installed in response to community concerns about speeding within the specific neighborhood and/or continuations of existing traffic safety projects. 

Surrey Downs

The first 20-mph speed limit was implemented in Surrey Downs (2020), a neighborhood just south of downtown. This deployment changed out one existing (and added two new) speed limit signs and replaced four (and added two new) existing “25 mph” pavement marking legends with “20 mph” pavement marking legends.

The work was performed by a contractor who had an on-call contract with the city and cost approximately $9,500. The community was notified of the change via direct mailer.

East Bellevue Greenway 

Following a successful “Healthy Streets” pilot in the Northeast Bellevue/Lake Hills neighborhood, the city created East Bellevue Greenway (2021), its first “neighborhood greenway,” making the street more attractive and safer for pedestrians and cyclists. In addition to operational changes at intersections that included paint-and-post neighborhood traffic circles, stop sign repositioning, and bicycle wayfinding, a 20-mph speed limit was introduced along the 1.9-mile corridor — a common practice along greenways. 

There were approximately four speed limit signs and four pavement marking legends replaced/added to reflect the 20-mph speed limit. The installation cost — as part of the wider contract to install all elements along the greenway — was about $5,000-10,000.

Eastgate/Tyee

The Eastgate/Tyee (2022) neighborhood was the largest deployment of a 20-mph speed limit in the city and was selected to be a continuation of previous projects (e.g., speed cushions, mini roundabout, sidewalk) aimed at addressing speeding concerns. Additionally, we wanted to test a lower speed limit that included a variety of different street contexts, such as wider streets, a larger geographic footprint, streets that traveled through a school zone, and keeping one local street at 25 mph due to a context that lent itself more to a collector arterial.

We added 18 new speed limit signs (at entrances off the higher speed arterials and a few mid-block locations on longer corridors in the neighborhood) and replaced 12 existing signs. The work was performed by a contractor who had an on-call contract with the city and cost approximately $33,000

Results of the Pilots

We knew data would be needed to show that changing the speed limit was effective and that the community liked the change. To that end, we collected before and after speed data for each deployment, with measurements taken at multiple locations in each neighborhood. Additionally, for the East Bellevue Greenway and Eastgate/Tyee pilots, we conducted surveys to better understand community sentiment around the speed limit change.

In each of the three deployments, we found reductions in high-end speeding — with no added enforcement — simply through the change in speed limit signs and community awareness. Results for each pilot are detailed below.

Surrey Downs

Speed studies recorded a 20% reduction in high-end speeding (those traveling 30 mph or more). Speed studies were recorded at seven locations and aggregated together to identify neighborhood-wide change.

East Bellevue Greenway

We found a drop in traffic traveling more than 25 mph following the speed limit reduction. Previously, 20.5% of traffic was measured traveling faster than 25 mph compared to 18.4% after the change. Speed studies were collected at four locations along the greenway. A comprehensive evaluation report found that that the speed limit change was the most popular deployment along the corridor.

Eastgate/Tyee

Speed studies recorded a 19% reduction in high-end speeding (those traveling 30 mph or more) despite a 7% increase in traffic volumes. Speed studies were recorded at nine locations and aggregated together to identify neighborhood-wide change. In addition to a reduction in speeds, a community survey revealed support for the speed limit change; nearly 60% of survey respondents thought that the change enhanced overall safety, with over 70% respondents indicating they slow down when they see the speed limit signs.

Next Steps

In Part 2 of this series, we will discuss how these neighborhood pilots set the stage for an effective citywide speed limit reduction. Topics to be covered will include outreach approach, council and other internal coordination, implementation considerations, and preparing for arterial speed management.