I-405 BRT South moves forward

The BRT station at NE 44th in Renton (image: WSDOT)

In October, WSDOT awarded the contract for the widening of I-405 between Bellevue and Renton. With significant construction beginning in the Spring, that kicks off construction on the first capital elements of I-405 BRT South. Meanwhile, WSDOT and Sound Transit have been making complementary investments along the corridor that continue to raise expectations for the success of the BRT. Recent briefings in Renton and Bellevue bring us up to speed on how the project is developing.

Direct access ramps and BRT stations on I-405, funded or existing in green, unfunded in blue (image: WSDOT)

In 2019, the Legislature approved Senate Bill 5825, making permanent the toll authorization for I-405 and SR 167 (and authorizing tolling for the Gateway facility in Pierce and South King County). The legislation also redefined I-405 and SR 167 as a single corridor with one account for toll revenue. Bonding was authorized for ETL toll revenues. The effect is to accelerate projects along the corridor. Most consequential for transit users is the second express lane north of Bothell which will enable dramatically faster bus operations in that area once combined with a Sound Transit project to add direct access lanes to Brickyard.

With toll funding confirmed and accelerated via bonding, several projects can move ahead to get the BRT delivered on schedule. The highway between Bellevue and Renton will be widened so it has two express toll lanes (one new lane and one converted from HOV-2), and will also add auxiliary lanes between exits in some areas. Preliminary work starts next week on several miles of paved trail that WSDOT is building along the Eastrail (Eastside Rail Corridor) including a crossing of I-405 that will open in 2021.

Also starting shortly is a BRT station and direct access ramps at NE 44th St in North Renton. This is an ST3 project funded by Sound Transit, though the cost is lower than a stand-alone project because Sound Transit only has to cover the incremental costs of adding the station and ramps to the highway widening project.

The neighborhood around that station site isn't particularly promising for transit today, but ridership will be boosted somewhat by 200 stalls of planned parking at the "Pan Abode" site on the SE corner. At the Renton meeting, Sound Transit staff mentioned discussions with Vulcan which owns the property. There were few details, but discussions about something more development-friendly than 200 surface stalls appear to be ongoing. Renton also favors including TOD along with the parking. That might mean a partnership that fits the transit parking within some larger development.

In South Renton, Sound Transit is in the process of acquiring the old Sound Ford property for the future South Renton Transit Center. The transit center will have 700 parking stalls and eight bus bays as well as bus layover space and a drop off area.

Preferred layout for the South Renton Transit Center (image: Sound Transit)

The site will also accommodate two acres of TOD on the west side of the property. The South Renton TC is envisioned as the likely future light rail station location. The parking structure and planned TOD are oriented east-west to accommodate the likeliest future orientation of a line from West Seattle. A study of this potential rail extension was funded in ST3.

Bus access to the transit center will be via Rainier Ave, with bus-only and BAT lanes at key bottlenecks between the station and the freeway. An alternative southbound path via Talbot and Grady was studied and performed poorly in AM peak traffic.

Planned South Renton Transit Center with parking structure in gray and potential future TOD in yellow (image: Sound Transit)

At 112th Ave SE in far-south Bellevue, WSDOT recently decided to add direct access ramps to the I-405 ETL project. That could allow another BRT station if Sound Transit funds the stops (probably an inexpensive addition as WSDOT is funding the ramp access). Sound Transit is currently evaluating the costs and ridership there. A transit stop on the ramps would allow BRT and Metro buses to serve the Metro-operated Newport Hills P&R without exiting the ETL. Currently, the stops are on the outside, and the 2020 service change will see some Sound Transit express buses skipping this P&R because it adds so much delay for through-riders.

Sound Transit may add another BRT station near the Newport Hills P&R in South Bellevue (image: WSDOT)

Sound Transit and WSDOT together are making a larger investment in the express toll lanes than was expected even a year or two ago. The 2019 Legislature's funding of the second ETL north of Bothell, together with investments by both agencies in direct access ramps to the ETL, promise much more robust BRT operations than envisioned by the ST3 program in 2016. Even more direct access facilities are contemplated. An extension of the NE 6th St overpass to 116th Ave NE is funded in Bellevue, and design is funded for direct access at NE 8th. BRT ridership estimates are up 22% in the south and about 30% better in the north vs the ST3 representative project. The ST3 plan envisioned a less built out ETL with buses operating in general traffic in more places.

WSDOT investments on I-405 are contributing to much faster expected travel times on transit when the BRT opens in 2024 (image: Sound Transit)