With approximately 12,000 vehicles entering the intersection daily, congestion is an issue at the four-way stop with existing operations at LOS F. Logan Park is located at this intersection and includes a ball field and play area with equipment for children. A paved walking path surrounds the park. The Snohomish County GMA Comprehensive Plan, including the Transportation Element (TE) included this intersection project on the Recommended County Arterial Improvement Project and is a designated future bicycle route on the Countywide Bicycle Facility System Map. It is identified in the Countys Transportation Needs Report as a High Priority and was first adopted into the Snohomish County 2017-2022 Six-Year Transportation Improvement Program (TIP). It is located in the Countys SWUGA which is forecasted to grow 34% by 2035 to a population of almost 600,000. This intersection improvement project is needed to improve the LOS deficiency from LOS F to LOS C forecasted for the PM commute in design year 2035. A no-build alternative was not acceptable due to failing LOS. This corridor is likely to fall into arrears without completion of the proposed improvements.
Projects — TIB Project Information
TIB Project Information
Snohomish County's Larch Way Roundabout
8-1-031(017)-1
8-1-031(017)-1
Larch Way Roundabout
Locust Wy and Logan Rd
FY 2024 Urban Arterial Program
Current Phase : Construction
Total TIB Funding : $2,875,000
County: Snohomish | Legislative District: 32 | Project Length: 0.14 | TIB Engineer: Greg Armstrong | Last Payment Date: 10/15/2024
Project Information
Lead Agency | SNOHOMISH COUNTY |
Funding Year | 2024 |
Program | UAP |
Current Phase | Construction |
Legislative District | 32, 1 |
Congressional District | 2 |
Federal Route Number | 2530 |
Project Length | 0.14 mi. |
ADT | 12,141 |
Functional Class | Minor |
Type of Work | Safety |
Project Contact | Ellora Larson |
Contact Email | Ellora.Larson@snoco.org |
TIB Engineer | Greg Armstrong |
Last Payment Date | 10/15/2024 |
Cultural Resource Assessment | CRA & BER |
Project Schedule
Target Date | Actual Date | |
---|---|---|
Project Selection Date | 12/02/2022 | |
Delayed Project Date | 01/01/2024 | |
DAHP Assessment Date | 10/27/2022 | |
Predesign Approval | ||
Design Approval | 02/01/2023 | 12/22/2022 |
Bid Auth. Approval | 01/01/2024 | 10/16/2023 |
Construction Approval | 01/30/2024 | 02/12/2024 |
Project Closeout | 06/30/2025 | |
Audit Date | ||
Withdrawn Date |
Project Funding
TIB Funds | Project Costs | |
---|---|---|
Environmental Study | 0 | 0 |
Design Study | 0 | 0 |
Total Predesign | 0 | 0 |
Special Study | 0 | 0 |
Design | 0 | 0 |
Right of Way | 0 | 0 |
Total Design | 0 | 0 |
Construction Engineering | 326,226 | 754,629 |
Construction Contract | 2,173,774 | 3,450,372 |
Other Construction | 0 | 0 |
Total Construction | 2,500,000 | 4,205,001 |
Funding Increase | 375,000 | |
Total TIB Funding | 2,875,000 | 4,205,001 |
Local Funding Partners
Funding Amount | Percent | |
---|---|---|
SNOHOMISH COUNTY | 1,330,001 | 31.6% |
WSDOT Funding | 0 | 0.0% |
Total Local Funding | 1,330,001 | 31.6% |
Project Description
This project constructs a single lane urban roundabout with a northbound slip lane at the Larch Way/Logan Road and Locust Way intersection, providing intersection operations of LOS C in 2035 (rather than no-build operations of LOS F) and avoids Swamp Creek environmental buffers. The projects roadway improvements include curbs, gutters, and a shared-use path. In 2006 and in 2016, engineers completed a traffic signal warrants analysis, turn lane warrants, queue lengths analysis, and LOS analysis. At the time of both analyses the intersections conditions warranted a traffic signal with an eastbound left turn and right turn lane as well as a westbound left turn lane. The intersection met the 4-hour vehicle volume, peak hour delay, and peak hour volume warrants resulting in the recommendation for a traffic signal or a roundabout. Synchro and SimTraffic modeling software were used to evaluate the operations of the stop-controlled and signalized intersection. Using 2035 volume forecasts, the analysis recommended left and right turn lanes at each leg of the intersection with the signal alternative. Due to Swamp Creeks environmental buffers, these turn lanes were not feasible. The final decision based on the Traffic Analysis was to construct a single lane roundabout with a northbound slip lane. This will prevent the corridor from falling into arrears.
Existing Condition
Project Benefits
- Improves safety;
- Relieves congestion;
- Removes ADA barriers
Project Delays
Delay Type | Resolution Date | Comments |
---|---|---|
No delayed project history. |