SR 520 - Eastside Transit and HOV Project - Completed fall 2015


SR 520 is a busy regional corridor that connects Seattle and key Eastside communities, including Bellevue, Kirkland and Redmond. Population and employment have grown dramatically in these communities in recent years, leading to increased traffic and transit demand. This rise in congestion – and a roadway designed for the 1960s – has led to frustrating commutes and unreliable transit travel times.

The Eastside Transit and HOV Project completed and improved the 2.3-mile HOV system from Evergreen Point Road in Medina to 108th Avenue Northeast in Bellevue. The improved six-lane corridor now includes two general-purpose lanes and one transit/HOV lane in each direction. The Eastside project also included construction of three community-connecting highway lids and two transit stations in the highway median.

An additional corridor upgrade is the regional bicycle and pedestrian path on the Eastside, which opened in early 2015. The path runs along the north side of SR 520 between Evergreen Point Road and 108th Avenue Northeast. After the new SR 520 floating bridge opened in April 2016, we extended the path to the west end of the new bridge. The path reached Seattle in late 2017 following completion of the West Approach Bridge North.

All major construction within the Eastside segment of SR 520 was completed in September 2015.

Project timeline

  • Spring 2010 - Completed environmental process.
  • 2010/2011 - Received permits.
  • Spring 2011 - Began construction.
  • Summer 2014 - Transit improvements open to drivers.
  • September 2015 - All Eastside improvements completed.

How you benefit

Relieves congestion

New inside HOV lanes between Lake Washington and 108th Avenue Northeast opened in September 2014. Buses and carpools continuing on SR 520 through the Eastside are now able to bypass congestion that occurs in the general-purpose lanes. This benefit is enhanced by the fact that the transit/HOV lane is located in the inside lane, eliminating conflicts between general-purpose drivers merging into the outside lane, and eliminating the need for buses to merge across traffic when accessing the transit stops, which include the new Evergreen Point Road median stop and the 92nd Avenue Northeast stop.

Other congestion-reducing improvements include the regional bicycle and pedestrian path, wider and safer shoulders, and direct-access ramps at 108th Avenue Northeast for carpools and transit.

Protects environment

  • Stream improvements and new, fish-friendly culverts on the Eastside, and wetlands restoration in Redmond's Bear Creek and Evans Creek areas.
  • Landscaping, including installation of nearly 20 raptor perches to encourage habitat development (read all about it on the WSDOT Blog), plus trees, shrubs and grasses.
  • Noise-reduction systems.
  • Stormwater detention and treatment facilities between Evergreen Point Road and 108th Avenue NE.

Partnerships & cooperation

WSDOT worked with the contractor, Eastside Corridor Constructors, and multiple municipalities surrounding SR 520’s Eastside corridor to understand community needs, reflect community ideas in the project’s design, and construct the improved corridor.


  • This project was fully funded by a variety of state and federal sources, including SR 520 tolling that began in December 2011.
  • We awarded a $306 million contract to Eastside Corridor Constructors for the Eastside project.
  • Visit the SR 520 Budget and Performance page for additional information.


Contact us


206-770-3554 (project info; staffed 8 a.m.-5 p.m., Mon-Fri)

SR 520 Bridge Replacement and HOV Program
999 3rd Avenue, Suite 2200
Seattle, WA 98104

Eastside project map
View larger map

photo congestion of WB 520
Prior to completion of new HOV lanes, evening congestion on westbound SR 520 near 92nd Avenue NE.