Notes
Appendix L of the Seattle-Tacoma International Airport (Sea-Tac Airport) Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTPs) Environmental Review, prepared by Zach Wieben of Concord Engineering for the Port of Seattle (submitted to Steve Rybolt and Nic Longo), dated September 9, 2024. Contains the Surface Transportation Existing Conditions Report analyzing traffic operations at 108 intersections (63 signalized, 41 stop-controlled, 4 uncontrolled) and freeway segments on SR 518 and I-5, using PM peak hour turning movement counts. Also includes attachments covering Synchro Level-of-Service (LOS) reports, SimTraffic queues and travel times, HCS LOS reports, and Approved Methods & Assumptions Documents. Analysis follows WSDOT Design Manual Chapter 320 Traffic Analysis procedures within the EA General Study Area (GSA).