WSDOT and the Federal Highway Administration (FHWA) signed the Environmental Assessment (pdf 13.45 mb) for the I-405, Tukwila to I-90 Vicinity Express Toll Lanes Project on July 3, 2018. A 30-day comment period ended on Aug. 9, 2018. 

The State Environmental Protection Act (SEPA) Determination of Non-Significance for the I-405, Tukwila to I-90 Vicinity Express Toll Lanes Project was also published on July 9, 2018.

Summary

• Project overview and context
• Summary of Environmental Assessment findings
• Information in Español (Spanish)

Documents for download

• Environmental Assessment (pdf 13.45 mb)

Discipline Reports

• Attachment A: Transportation Discipline Report (pdf 15 mb)
• Attachment B: Air Quality Discipline Report (pdf 10.25 mb)
• Attachment C: Noise Discipline Report (pdf 18.98 mb)
• Attachment D: Environmental Justice Discipline Report (pdf 15.25 mb)
• Attachment E: Cultural Resources Survey (pdf 12.81 mb)
• Attachment F: Visual Impact Assessment Discipline Report (pdf 11.16 mb)
• Attachment G: Water Resources Discipline Report (pdf 10.37 mb)
• Attachment H: Hazardous Materials Analysis (pdf 18.29 mb)
• Attachment I: Recreational, Section 4(f), and Section 6(f) Resources Technical Memorandum (pdf 15.89 mb)
• Attachment J: Geology, Soils, and Groundwater Technical Memorandum (pdf 12.18 mb)
• * Attachment K: Glossary
• * Attachment L: Acronyms and Abbreviations
• Attachments M-Q: Agency and Tribal Correspondence, Cross Reference of NEPA Elements, Logical Termini, Wetland and Water Resources Maps, and Endangered Species Act Summary (pdf 35.72 mb)

* Attachment K: Glossary and Attachment L: Acronyms and Abbreviations are included in the Environmental Assessment (pdf 13.45 mb).