Skip Top Navigation

SR 520 - Budget and Performance

Click to jump to a section below on this page:
520 budget overview
Revenue sources and cost estimates
Program performance and accountability
Tolling the floating bridge
SR 520 bond sales

SR 520 budget highlights:

Legislative spending cap for SR 520:

$4.65 B

Est'd cost, all planned improvements:

$4.56 B

Funding received to date:

$4.56 B

Major transportation projects often require innovative and complex funding solutions. The SR 520 Bridge Replacement and HOV Program is no exception. This page describes how the Washington State Department of Transportation is financing the construction of a new, safer floating bridge and other corridor improvements. Here you also will find updated information and useful links for measuring how the construction program is meeting its financial, operational and regulatory goals.

SR 520 budget overview

What is funded and under construction?
The $4.56 billion in SR 520 funding authorized by the Legislature pays for:

What is funded and not yet under construction?
The corridor's remaining improvements in Seattle are detailed on the I-5 to Lake Washington page; they include:

  • A new, six-lane Portage Bay Bridge, including an extension of a regional bicycle and pedestrian path from Montlake to I-5.
  • A new West Approach Bridge South for eastbound traffic connecting Seattle to the new floating bridge.
  • Two freeway lids in the Montlake and Roanoke neighborhoods.
  • A second bascule bridge over the Montlake Cut.

Revenue sources and cost estimates

How is WSDOT paying for the SR 520 Bridge Replacement and HOV Program?

SR 520 program legislative spending cap (set in 2009)

                 $4.65  B  

SR 520 program cost estimate

                 $4.56  B  

Funding received to date

                $4.56  B*

State funding (primarily gas tax)       

    $2.15 B               

SR 520 Account (tolling and future federal funding)

$1.65 B                

Federal TIFIA loan

$0.30 B                

Other federal funding

$0.20 B                

Deferred sales tax

$0.26 B                

*Includes $1.64 billion authorized in 2015 Connecting Washington legislation; $15 million authorized in 2015 transportation budget; and $10 million authorized in 2014 legislation. 

How does WSDOT calculate the cost of its construction projects?
Cost estimates are developed with the WSDOT Cost Estimate Validation Process (CEVP®). View more information about CEVP and Cost Risk Assessment here .

This WSDOT graphic (pdf 1.6 mb) compared the cost estimates made in 2010, 2012 and 2014 for the planned SR 520 improvements in Seattle between I-5 and the new floating bridge. See additional background materials (pdf 338 kb) on the SR 520 program's latest budget and cost estimate.

Program performance and accountability

Who oversees the performance of the SR 520 construction program?
Financial and operational oversight is provided by WSDOT management, the Governor's Office of Financial Management, the Office of the State Treasurer, the Washington State Legislature and the Federal Highway Administration.

Where can I learn more about SR 520 performance? 
Thumbnail of monthly construction report WSDOT publishes monthly reports containing updated information on the SR 520 program and its individual construction projects. These reports provide the latest program information, including:
• Construction progress, milestones, risks and challenges.
• Project budget and expenditure data, to date.
• Contractor performance measurements.
• Contractor compliance with safety and environmental regulations.
• Contractor compliance with apprenticeship and Disadvantaged Business Enterprise (DBE) regulations.

Find all SR 520 monthly construction progress reports in the SR 520 program library.

What has been spent so far on SR 520 construction?
Since 1997, WSDOT has invested nearly $2.1 billion – approximately 45 percent of the program's $4.65 billion legislative spending cap – on work to replace the aging SR 520 floating bridge and make other corridor upgrades. Additionally, $22 million was spent on the Trans-Lake Study.
Besides construction, the program's funds supported corridor planning, preliminary engineering, design, environmental review, and right-of-way purchases. We've made substantial progress. All bridge pontoons and Eastside improvements will be done in early 2015, the new floating bridge will open in 2016, and the West Approach Bridge North will open in 2017.

SR 520 expenditures to date

Trans-Lake Washington Study (1997-2003)


Early regional study

- Evaluated multiple options for a new Lake Washington crossing and decided on a new SR 520 floating bridge. (*not part of SR 520 program budget)

SR 520 Bridge Replacement and HOV Program


Preliminary engineering


- Addressed legislative requirements for reports, studies, and/or processes.
- Produced nine environmental documents needed for construction permits.
- Completed preliminary or conceptual design for the SR 520 corridor, pontoon casting facility, and pontoons.

Right of way


- Purchased properties necessary for construction or mitigation.



- Continued construction on Eastside, floating bridge, WABN, and pontoon projects.

Expenditures to date (as of Jan. 2015)


Additional financial information is posted in the Program Library under the Technical Documents section.

Are there other sources for getting SR 520 financial information?
Yes - WSDOT provides a variety of tools and resources to ensure transparency and public accountability for the SR 520 program information. These include:

Tolling the SR 520 floating bridge

When did tolling start on SR 520?
Tolling on the existing SR 520 bridge across Lake Washington began right after the bridge was completed in August 1963, and continued until the construction bonds were paid off in June 1979. The tolls generated approximately $60 million in revenue. Tolling restarted on the existing bridge on Dec. 29, 2011, to help fund construction of the new floating bridge.

Will the new floating bridge have tolls?
Yes, tolling on the new bridge will begin when it opens in spring 2016.

How long will SR 520 tolling last?
SR 520 tolling is projected to generate approximately $1.2 billion. That projection assumes tolling on the highway will last until 2056.

What do SR 520 tolls pay for?
Tolls collected on SR 520 help pay off bonds issued to reconstruct the highway. Tolls also pay for SR 520 operations and maintenance, debt service, future repairs, insurance, and deferred sales tax.

How do drivers pay tolls on SR 520?
The SR 520 corridor uses all-electronic tolling, meaning no toll booths and no stopping to pay. Tolls are collected electronically from those with a Good To Go! account as vehicles travel at highway speeds. The license plates of drivers without an account are photographed – these drivers can pay online within 72 hours of crossing or wait to receive a bill in the mail.

How were toll rates set?
The Washington State Transportation Commission set toll rates following the Washington Administrative Code process. Tolls on SR 520 vary by the day and time of travel.

For more information, visit SR 520 tolling.

SR 520 bond sales

Washington State bonds for the SR 520 program are sold in the public markets. Announcements of bond sales are posted on the website of the Office of the State Treasurer. Underwriters, if any, are identified at that time.

The state has no role in administering or interpreting the application of the EB-5 immigrant investor program and any SR 520 bonds sold under that program.

This section is in no way meant to be an endorsement of the EB-5 immigrant investor program. More information about the EB-5 program can be found here: EB-5 Immigrant Investor Program.