page_title: State Route 99 tunnel
section_title: Design and funding
hierarchical_section_title: State Route 99 tunnel / Design and funding
caption_attribution_description: Freighter Fairpartner anchored in Elliott Bay carrying the disassembled tunnel boring machine for the Alaskan Way Viaduct replacement tunnel
context_page_description: The State Route 99 tunnel, also known as the Alaskan Way Viaduct replacement tunnel, is a bored highway tunnel in the city of Seattle, Washington, United States. The 2-mile, double-decker tunnel carries a section of State Route 99 under Downtown Seattle from SoDo in the south to South Lake Union in the north.
  Since the 2001 Nisqually earthquake, the replacement of the Alaskan Way Viaduct had been the source of much political controversy demonstrating the Seattle process. Options for replacing the viaduct, which carried 110,000 vehicles per day, included either replacing it with a cut-and-cover tunnel, replacing it with another elevated highway, or eliminating it while modifying other surface streets and public transportation. The current plan emerged in 2009 when government officials agreed to a deep-bore tunnel.
  Construction began in July 2013 using "Bertha", at the time the world's largest-diameter tunnel boring machine. After several delays, tunnel boring was completed in April 2017, and the tunnel opened to traffic on February 4, 2019.
context_section_description: The approved design is a four-lane, 2-mile (3.2 km) long bored tunnel. The tunnel has a south portal in SoDo, near CenturyLink Field, and a north portal in South Lake Union, east of Seattle Center. The route goes beneath Pioneer Square, the central business district of Downtown, and Belltown.
  The project is estimated to cost US$3.29 billion, with $2.8 billion coming from the state and federal governments to cover the tunnel boring and a new interchange in SoDo.  The replacement project also includes the following projects and funding sources:
  The city of Seattle will fund surface street improvements, utility relocation, and repairs to the Alaskan Way Seawall, which was also damaged in the 2001 Nisqually earthquake.
  Since the proposed tunnel will contain two lanes in each direction as opposed to the viaduct's three, and no Western Avenue exit to serve the Belltown, Interbay, Magnolia, and Ballard areas, King County will fund transit improvements to offset the loss.
  The Port of Seattle approved a $267.7 million contribution.
  $200 million will be collected from tolls at rates set by the Washington State Transportation Commission with input from the Advisory Committee on Tolling and Traffic Management.
  WSDOT began part of the larger project in 2008, while the replacement debate was still on-going, by repairing some of the viaduct columns.
  The $80 million tunnel boring machine (TBM) Bertha was created for this project by Hitachi Zosen Corporation near Osaka, Japan. The 326 ft (99 m), 6,700-short-ton (6,100 t) TBM was disassembled into 40 pieces and shipped to Seattle where it was reassembled in the launch pit near the south end of the future tunnel. From there, the record-breaking 57.5-foot (17.5 m) diameter borer would move in 6.5 ft (2.0 m) increments toward the north end.
  WSDOT nicknamed the TBM "Bertha" after Seattle's first female mayor, Bertha Knight Landes.  This name was chosen from names submitted by kindergarten through 12th grade students for a naming competition.
caption: Freighter Fairpartner carrying the disassembled tunnel boring machine into the Port of Seattle
exif: {"Image Make": "Canon", "Image Model": "Canon EOS 5D Mark III", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop Lightroom 3.6 (Windows)", "Image DateTime": "2013:04:03 09:49:06", "Image Artist": "Orange Suede Sofa @ Wikipedia", "Image Copyright": "http://creativecommons.org/licenses/by-sa/3.0/", "Image ExifOffset": "316", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "962", "Thumbnail JPEGInterchangeFormatLength": "13979", "EXIF ExposureTime": "1/320", "EXIF FNumber": "71/10", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "640", "EXIF SensitivityType": "Recommended Exposure Index", "EXIF RecommendedExposureIndex": "640", "EXIF ExifVersion": "0230", "EXIF DateTimeOriginal": "2013:04:02 17:57:12", "EXIF DateTimeDigitized": "2013:04:02 17:57:12", "EXIF ShutterSpeedValue": "1040241/125000", "EXIF ApertureValue": "2827819/500000", "EXIF ExposureBiasValue": "-1/3", "EXIF MaxApertureValue": "4", "EXIF SubjectDistance": "4294967295", "EXIF MeteringMode": "Partial", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "300", "EXIF SubSecTimeOriginal": "00", "EXIF FocalPlaneXResolution": "160", "EXIF FocalPlaneYResolution": "160", "EXIF FocalPlaneResolutionUnit": "4", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF BodySerialNumber": "072024000469", "EXIF LensSpecification": "[300, 300, 0/0, 0/0]", "EXIF LensModel": "EF300mm f/4L IS USM", "EXIF LensSerialNumber": "0000000000"}