TagWSDOT(123)

This report analyzes existing traffic conditions around Seattle-Tacoma International Airport as part of the Sustainable Airport Master Plan (SAMP) Near-Term Projects Environmental Review. It examines 108 intersections—including signalized, stop-controlled, and uncontrolled locations—along key travel routes connecting the airport to surrounding communities, focusing on weekday PM peak hour traffic volumes. The study also includes freeway analysis of SR 518 and I-5 ramps and segments at the request of WSDOT.

This appendix outlines the traffic mitigation measures required for the Seattle-Tacoma International Airport Sustainable Airport Master Plan Near-Term Projects, as mandated by the FAA's Record of Decision and the Port of Seattle's State Environmental Policy Act Environmental Impact Statement. It details specific intersection improvements across multiple jurisdictions—including the City of SeaTac, City of Burien, City of Des Moines, and WSDOT—such as new traffic signals, roundabouts, and turn lane additions, along with proportionate-share cost contributions where full mitigation is not required. The measures are designed to address projected traffic impacts through 2037 and maintain acceptable levels of service at affected intersections near the airport.

WSDOT Aviation Division presentation outlining Advanced Air Mobility concepts in Washington State. Covers alternative energy sources, operation types, aircraft configurations, and size categories for AAM vehicles.

In an April 2026 letter to the FAA, the Washington State Department of Transportation provided detailed tax collection data and proposed spending offsets in response to federal questions about how Washington taxes aviation fuel. The letter covers Aircraft Fuel Tax revenues dating to 1983, local sales and use taxes on aircraft fuel tracked since 2023, and hazardous substance taxes, while explaining which taxes are grandfathered under federal rules. The state also outlined its methodology for calculating aviation-related budget offsets and committed to providing further updates within 60 days.

In March 2026, Washington State aviation and transportation officials exchanged emails revealing that the state faces approximately $210 million in aviation fuel tax liability after an FAA audit found it had been improperly diverting aviation fuel tax revenues to non-compliant uses. Even if all disputed expenditures—totaling about $32.6 million—were proven allowable, Washington would still be found in non-compliance, prompting the state's Aviation Director to recommend a proactive resolution strategy with the FAA. The correspondence also references federal law allowing state aviation fuel taxes to fund 'state aviation programs,' with ongoing debate about whether uses such as Sustainable Aviation Fuel development could qualify as compliant under that definition.

This document is an email chain from March 2026 between Washington State Department of Transportation (WSDOT), the Governor's Office, and the FAA regarding Washington State's compliance with federal aviation fuel tax requirements. WSDOT missed a February 18, 2026 deadline to provide information requested by the FAA, and the FAA subsequently issued a demand warning that compliance and enforcement actions would follow if the information was not received within 10 days. WSDOT officials indicated they do not have the ability to provide the requested information and sought guidance from the Governor's Office and the Office of Financial Management.

These emails document a 2025–2026 federal compliance matter in which the FAA reviewed Washington State's aviation fuel tax practices to determine whether they met federal revenue-use requirements. After Washington missed a February 18, 2026 response deadline, the FAA notified state officials at the Department of Revenue and WSDOT, prompting coordination between multiple state agencies. While related to aviation finance rather than airport noise policy directly, the correspondence reflects ongoing federal oversight of Washington State's aviation funding obligations.