SR 520 Eastside Transit and HOV Project - Complete Summer 2015

Plans and Process

SR 520 is a busy regional corridor that connects Seattle with cities east of Lake Washington, including Bellevue, Kirkland and Redmond. In recent decades, Eastside cities have experienced dramatic population and employment growth, leading to increased traffic and transit demand. This overall rise in congestion – on a roadway designed for the 1960s – led to frustrating commutes and unreliable travel times for transit riders and motorists.

Community engagement influences project design

The Eastside Transit and HOV Project was part of the larger, ongoing SR 520 Bridge Replacement and HOV Program. The SR 520 Program is rebuilding SR 520 from I-405 in Bellevue to I-5 in Seattle. Design features for the rebuilt Eastside corridor were refined through various community engagement processes. These processes included local government partners, design professionals and community members. Their input significantly influenced the final design of key project elements. Examples include the Eastside’s three freeway lids, noise walls and the shared-use SR 520 Trail.

You can read SR 520 design reports and summaries of key design processes on the SR 520 Program Community Engagement tab.

Other completed SR 520 projects

Other completed phases of the larger SR 520 Bridge Replacement and HOV Program involved:

• Pontoon Construction Project, which built 33 of the new floating bridge’s pontoons, including its massive “longitudinal” pontoons, in Aberdeen, Washington.
• Floating Bridge and Landings Project, which built the world’s longest floating bridge on Lake Washington between Seattle and the Eastside, and 44 of the bridge’s smaller pontoons in Tacoma.
• West Approach Bridge North Project, which completed the first of two parallel west approach bridges over Union Bay, between the floating bridge and Seattle’s Montlake neighborhood.

When the corridor’s reconstruction finishes in approximately 2030:

• All of SR 520’s major bridges will be replaced with stronger structures.
• Bus/carpool lanes and a regional bicycle/pedestrian path will extend from Seattle east to Redmond.
• Travelers will have safer access ramps and improved connections to transit, local streets, and local shared-use trails.

How you benefit

The original SR 520 corridor, opened in 1963, had just two lanes in each direction. It also had no shoulders for disabled vehicles, no bus/carpool lanes, and short on-ramps that added risk for merging traffic. In the 1970s, a converted right shoulder became a westbound transit lane between 108th Avenue Northeast and Evergreen Point Road. The region’s growing economy and population, particularly on the Eastside, caused steadily worsening congestion and longer commutes on SR 520. This was especially true during peak travel times.

The reconstructed Eastside segment of SR 520 provides a safer and more reliable travel connection between the Eastside and Seattle. These changes, together with the corridor’s other, ongoing improvements, will enhance travel for motorists and transit riders. A new, wide bike and pedestrian trail alongside the highway also provides a non-motorized travel option for commuting and recreation. The reconstructed Eastside corridor provides numerous additional public benefits, including:

• Congestion relief with two general-purpose lanes and one transit/HOV lane in each direction. This provides bus riders and carpoolers more reliable travel, while also freeing up space in the general-purpose lanes for drivers.
• Improved travel options with the addition of a 14-foot-wide, cross-lake bicycle and pedestrian path, with connections to local and regional trails on either side of Lake Washington.
• Safer, easier bus access for transit riders with ADA-compliant, median transit stations at Evergreen Point Road and 92nd Avenue Northeast.
• Improved access for buses and carpools from direct-access ramps at 108th Avenue Northeast, which make entering and exiting the highway safer and more reliable. In addition, the new transit/HOV lanes are the inside lane, eliminating conflicts with traffic in the general-purpose lanes and providing safer bus access to the median transit stations.
• Fewer traffic backups from the addition of wider, safer shoulders and longer on- and off-ramps with improved sight lines. The widened shoulders allow disabled vehicles to pull over and not block traffic.
• Environmental enhancements within the corridor, including a new system that captures the Eastside corridor’s highway runoff and naturally filters out stormwater pollutants. The project also installed eight large culverts to aid fish migration.

The SR 520 Program has participated in numerous mitigation projects to protect the natural environment of the greater Lake Washington watershed. Learn more about these projects and other environmental benefits on our SR 520 Environment tab.