Project Number: 3121-01
From milepost 1.998 to milepost 2.302
RATA Funds: $1,086,120
Legislative District: 39
Status: PE and Design
Date Approved: 2021
Importance: The 84 St NE corridor serves as a major east-west connection between two State Highways (SR 9 and SR 92) and two cities (Marysville and Granite Falls). The posted speed is 50 mph and the 85th percentile speed is 56 mph. The ADT at 84 St NE / 123 Ave NE is 10,700. In the County's 2015 GMA Comprehensive Plan Update, the 84 St NE corridor was designated as a rural arterial with urban traffic.
Deficiencies: From 2010 - 2019 there have been 22 collisions, 15 total injuries, and 3 serious injuries that fall within the footprint of the proposed improvements. Specifically, at the intersection of 84 St NE / 123 Ave NE there have been 12 collisions with 12 total injuries and 2 serious injuries. Proposed Improvements: In 2019 Snohomish County completed a safety study for the 84 St NE corridor that resulted in a list of highly effective countermeasures proposed for consideration along this corridor. Among the highly effective treatments recommended was the construction of roundabouts at 9 major intersections. A benefit / cost analysis was performed for the roundabout alternatives at each intersection resulting in the realization that the intersection of 84 St NE / 123 Ave NE had the highest benefit / cost value compared to all other intersections along the corridor for roundabout projects.