Transportation Committee Recap: Three I-405 Projects, One Pick, and a $450 Million Gap

Bellevue Chamber of Commerce  |  September 3, 2026

Our September transportation committee meeting welcomed  WSDOT's I-405 and SR 167 team. They shared with us that of the three Bellevue interchange projects studied for the next Renton-to-Bellevue construction contract, the Coal Creek Parkway roundabouts were selected to move forward. The Northeast 6th Street extension and the Lake Hills Connector southbound on-ramp stay in the corridor's long-range plan, with no funding currently attached.

Three projects, one contract

The 2025 legislative session authorized about $180 million in toll revenue for what the program calls Contract 3. Pre-design work with the city priced three candidates in year-of-expenditure dollars and modeled their 2035 traffic effects.

A Northeast 6th extension, bridging northbound I-405 to tie the direct access ramps to 116th Avenue, came in a little under $400 million. The Lake Hills Connector southbound on-ramp priced at about $165 million. The Coal Creek roundabouts, rebuilding the freeway ramps plus 119th and 120th Avenues, were priced at a little over $100 million in the same dollars. Modeled daily delay reductions in 2035 ran 310 vehicle hours for Northeast 6th, about 100 for Lake Hills, and about 880 for Coal Creek. The roundabouts carried by far the largest delay reduction at the lower end of the cost estimates.

Why Coal Creek came out first

"There's a limited amount of funding available over the period of time that we're talking about. And so we really did have to look at a cost benefit on these, which is where Coal Creek came out." — Deputy Program Administrator, I-405/SR 167 Program

The committee pressed on the analysis rather than the arithmetic. Bellevue is concentrating the bulk of its growth downtown and in Wilburton and Bel-Red, members noted, and setting the two Wilburton-area projects aside leaves that growth without the state improvements meant to absorb it. The committee asked whether the 2035 projections hold, and whether they drove the conclusion. The team confirmed the land use assumptions were built with city staff.

"These projects all are beneficial and all are needed projects that are part of the 405 master plan vision for the corridor." — Director of Design, I-405/SR 167 Program

Under construction now

The Renton to Bellevue widening already underway adds one lane in each direction, coupled with the existing HOV lane to create a dual express toll lane system between Bellevue and SR 167. That closes the missing link in the managed lanes running north to Lynnwood and completes a 50-mile system, and the segment is expected to open to traffic by summer 2027. 

What the committee asked for

The committee closed with three requests: the master list of I-405 interchange projects, the screening criteria behind the prioritization, and the benefit summaries underneath each option. The committee framed the September 22 joint session with the Chamber's Policy Council as where that work lands, bracketed by the city's budget hearings on September 15 and October 27.