What is the approved budget of SR 99 tunnel?
The SR 99 tunnel is a two-mile, double-deck highway tunnel carrying State Route 99 beneath downtown Seattle between the stadium district and South Lake Union. It replaced the central-waterfront section of the earthquake-vulnerable Alaskan Way Viaduct. WSDOT selected the bored-tunnel alternative in 2009, Bertha began tunnelling on 30 July 2013, completed the bore on 4 April 2017, and the tunnel opened to traffic on 4 February 2019. WSDOT reports a $2.15 billion budget for the tunnel project, including the design-build tunnel, its north and south access roads, north-portal streets and the later South Access surface connections. That scope is distinct from the $3.35 billion Alaskan Way Viaduct Replacement Program of more than 30 projects.
Approved budget
$2.15 billion
Cost basis: 2024
Cost record
How the cost changed
Budgets, contracts and final costs may cover different stages. Each figure keeps its own year and source.
Approved budget
2024$2.15 billion
wsdot.wa.govFinancing amount
2012$200 million
wsdot.wa.govProject metrics
Key dimensions
- Total lengthWashington State Department of Transportation
- 2,832.4454 m
Project record