43rd Ave SE/Sunset Rd

December 2022 Update

Per the Snohomish County Council-approved 2023-2028 Transportation Improvement Plan, the county is planning to construct the 43rd Ave SE project in phases due to funding availability and permitting timing. Please view the project area map in the sidebar and description of the phases below. 

Phase I: 188th St SE to 180th St SE and a roundabout at SR 524

Phase II: 204th St SE to 188th St SE

In November 2022, the county was awarded a $4 million Washington State Public Works Board Construction Loan, which helped Phase I move forward to construction. 

Utility relocations will continue intermittently until project construction begins. Single-lane closures and shoulder closures are expected during the utility relocation work. Purchase of temporary construction rights and right of way is underway for both construction phases.


Snohomish County Public Works proposes to construct arterial improvements to approximately 1.7 miles of 43rd Ave SE from SR 524 (Maltby Road) to Sunset Rd at 180th St SE. Construction includes the following primary elements:

  • Widen 43rd Ave SE from SR 524 north to 188th St SE to a two-lane rural section, including a separated pedestrian facility and shoulders
  • Add approximately 1,400 linear feet of new county rural road to connect 200th St SE and 196th St SE
  • Improve the existing urban section of 43rd Ave SE from 188th St SE north to 184th St SE
  • Add approximately 450 linear feet of new county urban road between 184th St SE and 42nd Dr SE
  • Install two new roundabouts on 43rd Ave SE at SR 524 and at 196th St SE
  • Install new traffic signal and turn pockets at 180th St SE and Sunset Rd
  • Add two new stormwater ponds and two underground stormwater chambers
Improvement to the rural segment of 43rd Ave SE will follow the Snohomish County Engineering Design and Development Standards for a rural roadway section, which have been developed to help maintain the rural character of the area consistent with the local and regional guidance. To address the specific needs of residents in the vicinity of 43rd Ave SE, we are proposing a pathway separated from the travel lanes. 

Project Background

The Growth Management Act (GMA) requires Snohomish County to develop a Transportation Element (TE) as part of the Comprehensive Plan, which is used as a guide for future roadway needs. The 43rd Ave SE/Sunset Rd project has been in the Comprehensive Plan since 2005 and is currently in the council-approved Annual Construction Plan (ACP) and council-approved Six-Year Transportation Improvement Program (TIP). The role of 43rd Ave SE has been defined in the TE as a minor collector, which in the county system is a type of arterial road. The purpose of a minor collector, is “funneling traffic from local roads to the arterial network and providing a higher level of property access.” It is common to have minor collectors within both urban and rural residential neighborhoods. The current condition of 43rd Ave SE is preventing it from fulfilling its role as a collector. The purpose of the 43rd Ave SE project is to improve the existing road section to collector standards, reduce delay, improve safety and intersection operations, promote multi-modal mobility throughout the corridor, and improve the overall effectiveness of the county’s road system.  


  • 2016-2018: Completed field survey and preliminary design 
  • 2019: Environmental studies
  • October 2019: Completed traffic noise study
  • December 2019: Public open house
  • 2020-2025: Design, right-of-way acquisitions and utility relocations
  • 2026-2027: Construction of Phase 1 to start in 2026, subject to permitting.
  • 2028-2029: Construction of Phase II to begin in 2028, subject to funding availability


The proposed design, right-of-way, and construction will be funded by the Snohomish County Road Fund and a Washington State Public Works Board Loan. In November 2022, the county was awarded a $4 million Washington State Public Works Board Loan which helped to secure funding for construction of Phase I. The county will pursue grants and other funding opportunities to fund the project.

Environmental Review

An environmental review and checklist was completed in compliance with the State Environmental Policy Act (SEPA) on January 23, 2020, for 43rd Avenue SE corridor improvement project.
Snohomish County Public Works determined that this project does not have a probable, significant adverse impact on the environment and issued a Determination of Non-significance (DNS) on February 14, 2020.

SEPA Appeal Period
This DNS may be appealed pursuant to the requirements of SCC 30.61.300 and Chapter 2.02 SCC. There is a 14-day appeal period for the SEPA DNS that commences from the date of publication of notice and ends on March 2, 2020. Any appeal must be addressed to the County Hearing Examiner, accompanied by a filing fee of $500.00, and be filed in writing at Snohomish County Public Works, 3000 Rockefeller Ave., Robert J. Drewel Building, 2nd Floor, Customer Service Center, Everett, Washington. The appeal period closed on March 2, 2020. The SEPA comment period regarding this project ended on March 9, 2020.

Public Comment
The LDA permit application is subject to a 21-day public and agency comment period. The comment period closed on March 9, 2020. 

Open House - December 5, 2019

Open House - June 27, 2017


Other Projects in the Area

In addition to the 43rd Ave. SE project, the county is working on improvements to other nearby corridors including: