Notes
Traffic operational analysis memorandum submitted by Zach Wieben of Concord Engineering to Port of Seattle (Steve Rybolt, Nic Longo), dated September 9, 2024, for the Seattle-Tacoma International Airport Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTPs) Environmental Review, Affected Environment chapter. Analyzes existing conditions at 108 intersections (63 signalized, 41 stop-controlled, 4 uncontrolled) plus SR 518 and I-5 freeway ramps and segments in the General Study Area (GSA). Analysis uses weekday PM peak hour (4–6 p.m., Tuesday–Wednesday–Thursday) per WSDOT Design Manual Chapter 320. Tools include Synchro, SimTraffic, and HCS Level-of-Service (LOS) reports. Attachments include turning movement count graphics, Synchro LOS reports, SimTraffic queues and travel times, HCS LOS reports, and Approved Methods & Assumptions Documents.