The SR 520 Bridge Replacement and HOV Program includes important safety, mobility and community improvements throughout the SR 520 corridor and around Lake Washington. When complete, the new SR 520 corridor will include safer bridges and structures and a six-lane corridor from Seattle to Redmond that includes inside transit/HOV lanes and a bicycle/pedestrian path. We've developed this map to display key project benefits and commitments we've made to local communities, jurisdictions and resource agencies.
How to use this map:
To learn more about a particular topic, click a topic button to the left of the map. Click any of the flags for additional information. If information becomes too cluttered, you can toggle topics on or off.
Questions? Email us at sr520bridge@wsdot.wa.gov.
WSDOT proposed to enhance the shoreline by removing bulkhead structure along the shoreline, replanting shoreline vegetation, and supplementing gravel in Lake Washington to improve salmon habitat. The mitigation proposed at Seward Park continues work previously begun by the Seattle Parks Department.
Total area of aquatic mitigation: 2.69 acres
Proposed mitigation at Taylor Creek calls for stream and delta restoration by reconstructing the channel, establishing an active and accessible floodplain, and planting the riparian buffer with native vegetation. This work is a continuation of the stream restoration proposed and being pursued by Seattle Public Utilities at the site and upstream of Rainier Avenue.
Total area of aquatic mitigation: 0.97 acres
Proposed mitigation at this site includes restoring shoreline vegetation, enhancing shoreline, and removing structures, which will improve conditions for salmon migrating from the Cedar River (located adjacent to the site) to Lake Washington and Puget Sound.
Total area of aquatic mitigation: 3.97 acres
WSDOT will work with the City of Redmond to improve salmon habitat by restoring portions of Bear Creek, through re-alignment and reconstruction of the channel, riparian and floodplain restoration, and planting of native riparian vegetation.
Total area of aquatic mitigation: 15.78 acres
WSDOT proposes to improve salmon habitat at the East Approach of the new SR 520 floating bridge. This work will include removing structure and bulkhead, supplementing spawning gravel, and restoring shoreline.
Total area of aquatic mitigation: 0.89 acres
Mitigation type: Parks
WSDOT will coordinate with the University of Washington and Seattle Parks Department to develop this site as a recreational resource. This site will provide approximately four acres of public space, and will meet recreational and access needs required by the National Park Service and the Washington Department of Fish and Wildlife. Further details and a conceptual drawing of the site can be found in the Environmental Evaluation of Section 6(f) Replacement Sites, an attachment to the Final Environmental Impact Statement. Actual design plans are subject to permitting and development needs of the City of Seattle and University of Washington.
Total area of parks mitigation: 4 acres
Mitigation type: Parks/Wetland
WSDOT will coordinate with the Arboretum and Botanical Garden Committee and the Seattle Parks Department to implement mitigation required by state and federal law. Proposed mitigation measures are outlined in the 2010 Washington Park Arboretum Mitigation Plan.
Proposed mitigation at the Union Bay Natural Area includes wetland enhancement and establishment, which consists of grading, removing invasive and non-native species, replanting with native species, and enhancing wetland buffers. The proposed mitigation supports and continues work previously begun by the University of Washington as part of the Union Bay Natural Area Master Plan.
Total area of wetland mitigation (including wetland buffer enhancement): 25.70 acres
Proposed mitigation at the WSDOT Peninsula will include wetland re-establishment in a historically dredged area, wetland enhancement through the removal of existing invasive and non-native species, grading, replanting with native vegetation, and wetland buffer enhancement. The proposed mitigation also includes establishing wetland in previously dredged areas.
Total area of wetland mitigation (including wetland buffer enhancement): 9.04 acres
WSDOT proposes to conduct both wetland and aquatic mitigation at Magnuson Park. Proposed wetland mitigation includes wetland establishment and enhancement, which consists of grading, removal of existing invasive or non-native species, replanting with native vegetation, and enhancement of wetland buffers. Proposed aquatic mitigation includes shoreline enhancement, which involves removing structure along the shoreline, replanting with shoreline vegetation, and supplementing gravel. The proposed mitigation continues work previously begun by the Seattle Parks Department as part of the .
Total area of aquatic mitigation: 1.55 acres
Total area of wetland mitigation (including wetland buffer enhancement): 19.82 acres
WSDOT proposes to conduct both wetland and aquatic mitigation at the Elliott Bridge Reach site, located on the Cedar River. The proposed combined mitigation would include lowering the existing levee to allow overbank flows, removing floodplain fill material behind the levee, and establishing a forested floodplain-wetland mosaic. Components of the aquatic mitigation will also include restoring gravel bar habitat and creating an off-channel backwater slough with large woody debris elements. The site will be planted with native vegetation, and a setback levee will be constructed to protect adjacent infrastructure and downstream residences.
Total area of aquatic mitigation: 4.16 acres
Total area of wetland mitigation (including wetland buffer enhancement): 4.27 acres
The columns of the Portage Bay Bridge are hollow, do not meet current seismic design standards and are vulnerable to catastrophic failure in an earthquake.
The new Portage Bay Bridge will be built to current seismic design standards and will be better able to withstand an earthquake.
This project element is currently unfunded for construction.
The columns of the west approach bridge are hollow, do not meet current seismic design standards and are vulnerable to catastrophic failure in an earthquake.
The new west approach bridge will be built to current seismic design standards and will be better able to withstand an earthquake.
This project element is currently unfunded for construction.
The Evergreen Point Bridge and its approaches are in danger of structural failure in a windstorm, and need to be replaced.
The new SR 520 floating bridge will be built to better withstand windstorms, reducing the risk of catastrophic failure. Construction will start on Lake Washington in 2012 and the new bridge will open to traffic as soon as December 2014.
View images of the new SR 520 floating bridge
This project element is funded for construction.
The Montlake Triangle Project will provide improved connections for transit riders, bicyclists and pedestrians to the University of Washington campus and medical center, the future University Link light rail station, athletic facilities, and surrounding communities.
The new Evergreen Point Road lid will include an improved transit stop in the middle of the highway, providing a safer, more efficient transit-riding experience.
This project element is funded for construction.
The new 92nd Avenue Northeast lid will include an improved transit stop in the middle of the highway, providing a safer, more efficient transit-riding experience.
This project element is funded for construction.
The new Montlake lid will provide a convenient and improved waiting area for transit passenger transferring between local bus service and highway bus service. It will also allow for buses to use direct-access ramps that connect directly to and from the transit/HOV lanes east of the lid.
This project element is currently unfunded for construction.
WSDOT is coordinating with the City of Seattle to evaluate timing for construction of a new Montlake bridge that would be built to the east of the existing bridge.
When constructed, the new bridge will allow WSDOT to provide transit/HOV lanes on Montlake Boulevard between SR 520 and the University of Washington.
This project element is currently unfunded for construction.
The new SR 520 includes a direct connection for buses and carpools to enter I-5 express lanes, headed from the Eastside to downtown Seattle in the morning, and from downtown Seattle toward the Eastside in the evening.
This project element is currently unfunded for construction.
The new SR 520 corridor will improve mobility with two general-purpose lanes and one transit/HOV lane in each direction, as well as a bicycle/pedestrian path on the north side of the floating bridge.
When complete, the new SR 520 corridor will provide the following key regional transportation benefits:
Bicyclists and pedestrians will be able to use an improved, wider bicycle and pedestrian crossing over I-5.
This project element is currently unfunded for construction.
WSDOT and SDOT are developing a Neighborhood Traffic Management Plan for the Seattle neighborhoods around the SR 520 project area in order to identify solutions to neighborhood traffic concerns related to the SR 520 project.
This process will identify issues and solutions through an advisory group, define traffic management measures to proactively reduce SR 520 project construction effects, and develop long-term traffic management strategies.
Stay tuned for more about how to get involved in the community advisory group and other public outreach opportunities for the plan.
We will build components for the new SR 520 floating bridge at an existing site in Kenmore without the need to develop a new industrial site. Crews will build bridge anchors and hundreds of precast concrete deck panels for the new floating bridge.
WSDOT will reconnect communities divided by construction of the original SR 520 with a new lid at 10th Avenue Northeast and Delmar Drive Northeast.
This project element is currently unfunded for construction.
WSDOT is planning a new lid at Montlake Boulevard with improved transit connections and opportunities for open space.
This project element is currently unfunded for construction.
This fall we started the Seattle Community Design Process, a series of interactive public sessions where members of local communities can come and talk with project staff, learn more about the project, and share their ideas about design elements for the new SR 520 corridor from I-5 to the floating bridge.
More information is available on our project website.
WSDOT included sustainability priorities in contract documents for the new floating bridge, including reducing greenhouse gas emissions, reusing and recycling materials, using existing industrial facilities or Brownfield sites, minimizing aquatic impacts and measuring, monitoring and reporting results
Kiewit-General-Manson included several measures to address sustainability priorities, including:
Eastside construction crews are currently recycling plastic materials, wood, metals, concrete and asphalt. Approximately 94% of material sent off-site has been recycled.
WSDOT and the construction contractor will develop a community construction management plan (CCMP) for each funded phase of project construction. A CCMP is a set of tools and commitments to help minimize the effects of construction on the public by providing timely and responsive information, as well as implementing standard specifications and best practices. A CCMP is in development for the floating bridge and landings portion of the corridor, which has received funding for construction.
A CCMP will be developed with public input for each future construction phase in Seattle that receives funding.
WSDOT and the construction contractor will develop a community construction management plan (CCMP) for each funded phase of project construction. The CCMP is a set of tools and commitments to help minimize the effects of construction on the public by providing timely and responsive information, as well as implementing standard specifications and best practices.
WSDOT has worked with local communities to develop the design of a new community-connecting lid at Evergreen Point Road. The lid features a median transit stop, a park and ride lot, and new open space. It will reconnect communities divided by construction of the original SR 520 highway and provide convenient access to the new median transit stop.
This project element is funded for construction.
WSDOT has worked with local communities to develop the design of a new community-connecting lid at 84th Avenue Northeast. The lid features new open space and a roundabout interchange. It will reconnect communities divided by construction of the original SR 520 highway.
This project element is funded for construction.
WSDOT has worked with local communities to develop the design of a new community-connecting lid at 92nd Avenue Northeast. The lid features a median transit stop, a passenger drop-off, new open space and a roundabout interchange. It will reconnect communities divided by construction of the original SR 520 highway and provide convenient access to the new median transit stop.
This project element is funded for construction.
We are building a direct-access ramp to allow a direct connection to and from SR 520 for transit and HOV vehicles.
A new direct-access ramp here will improve access to and from the South Kirkland Park and Ride.
This project element is funded for construction.
Major construction elements of the SR 520 program end near 108th Avenue Northeast and the I-405 interchange. We are also planning to restripe the existing transit/HOV lanes from the outside to the inside from I-405 to the SR 202 interchange in Redmond. When all program improvements are complete, there will be a continuous inside SR 520 transit/HOV lane from Seattle to Redmond.
This project element is funded for construction.
Today, water from the SR 520 roadway current enters Lake Washington untreated. We are planning storwmwater treatment facilities throughout the corridor to catch and prevent highway pollutants from entering Lake Washington.
In order to improve fish passage for migrating salmon, we’re building nine improved culverts from Medina to Bellevue. Six of these culverts will cross beneath the mainline lanes of the highway and three will be beneath adjacent city streets.
This project element is funded for construction.
We've planned a number of elements to help minimize noise from I-5 to Medina:
The following project design elements may further reduce noise:
We will build new walls between Evergreen Point Road and Bellevue Way to help reduce noise and provide screening for Eastside residents. Planned walls will range between 4 and 24 feet high, depending on location.
More information, including planned wall locations, is available on our website.
The new six-lane highway from I-5 in Seattle to SR 202 in Redmond will include wider, safer shoulders throughout the corridor, allowing room for disabled vehicles to pull over without blocking moving traffic. Merge distances will also be improved, providing longer distances and safer merges for vehicles entering and exiting the highway.
Bicyclists and pedestrians will be able to cross Lake Washington on a shared-use path built on the north side of the new floating bridge.
The Evans Creek wetlands mitigation site will help create and restore valuable wetland habitat.
Activities at the site may include creating new stream channels, reconnecting streams with their associated floodplains, controlling invasive species, establishing native vegetation, shading new stream channels to provide for wildlife habitat, and creating greater habitat structure and diversity.
