West Seattle and Ballard Link Extensions Initial assessment results System Expansion Committee | 09/12/2019
Why we are here • Review initial assessment of potential additional alternatives suggested during the EIS scoping period. • Inform a future decision on whether the alternatives should be studied further in the Draft EIS. 2
May 23rd Board Action Identified Draft EIS alternatives: • Preferred Alternatives • Preferred Alternatives with Third Party Funding • Other Draft EIS alternatives Board also requested initial assessment of potential additional alternatives suggested during EIS scoping period 3 3
Initial assessment 20 th Ave Tunnel alternatives Ballard • Yancy/Andover Elevated • Pigeon Point Tunnel • SODO Elevated • 20th Ave Tunnel Ballard SODO Yancy/Andover Elevated Elevated Pigeon Point Tunnel 4 4
Initial assessment timeline Sound Transit Board Sept. 12 Initial Assessment evaluation results and next steps System Expansion Committee Evaluation Information Online Sept. 13 – Oct. 4 Initial Assessment evaluation results and next steps Comment form / Community briefings Sound Transit Board Sept. 26 Initial Assessment evaluation results and next steps Full Board Sound Transit Board Initial Assessments – potential action Oct. 10 System Expansion Committee Establish whether further study in DEIS is appropriate Sound Transit Board Initial Assessments – potential action Oct. 24 Full Board Establish whether further study in DEIS is appropriate 5
Initial assessment results
Evaluated using criteria from Level 3 • Reliable service • Financial sustainability • Travel times • Historically underserved populations • Regional connectivity • Station area land use plan consistency • Transit capacity • Modal integration • Projected transit demand • Station area development • Regional centers served opportunities • ST Long-Range Plan consistency • Environmental effects • ST3 consistency • Traffic operations • Technical feasibility • Economic effects 7
Initial assessment alternatives Yancy/Andover Elevated 20 th Ave Tunnel Ballard SODO Elevated Pigeon Point Tunnel N 8
Initial assessment alternatives Descriptions Key considerations 9
Initial assessment alternative Yancy/Andover Elevated N 10
Description: Yancy/Andover Elevated Delridge Station north of Andover Elevated along Andover Street and Avalon Way Connects to south Duwamish crossing Connects to elevated N Avalon Station 11
Key considerations: Yancy/Andover Elevated Less accessible Delridge Increases potential station location business and freight effects Additional curves on high guideway with steep grades Lessens potential residential effects overall, but increases along Avalon Way Similar comparative estimate as ST3 N Avoids Golf Course Representative Project 12
Initial assessment alternative Pigeon Point Tunnel N 13
Description: Pigeon Point Tunnel Crosses Duwamish south of existing West Seattle Bridge Connects to tunnel alternative to West Seattle Junction Tunnel through Pigeon Point Further south Delridge station N location 14
Key considerations: Pigeon Point Tunnel Avoids proximity to West More direct route and Seattle Bridge and BNSF avoids steep grades railroad bridge Fewer potential business and freight effects Tunnel lessens Less area affected in Duwamish visual effects Greenbelt, but bisects habitat area; closer to known archaeological site Requires 3 rd Party funding (+ $900 M*) Similar potential Includes two tunnels: More accessible station residential effects, due to south location West Seattle Junction Tunnel but at different N (+ $700 M*) and Pigeon Point and lower height locations Tunnel (+ $200 M*) 15 * Compared to ST3 Representative Project
Initial assessment alternative SODO Elevated N 16
Initial assessment alternatives not carried forward Double Elevated Partial Elevated (refinement) N 17
Description: SODO Double Elevated Elevates new and existing SODO Station and light rail lines Maintains Lander and N Holgate at-grade 18
Key considerations: SODO Double Elevated Facilitates transit integration with E3 busway maintained Maintains existing Lander Requires lowering of Holgate and platform closer to Lander Street at-grade Street for guideway clearance Constructs two elevated guideways in poor soils; increased potential Requires two shutdowns of Central business effects Link during construction; could Requires 3 rd Party funding disproportionately affect minority and N low-income populations (+ $300 M*) 19 * Compared to ST3 Representative Project. Estimate is + $500 M compared to Preferred Alternative (SODO At-Grade).
Description: SODO Partial Elevated (refinement) Elevates new light rail line and SODO Station; maintain existing light rail at-grade Maintains Lander at-grade; includes Holgate roadway overcrossing N 20
Key considerations: SODO Partial Elevated (refinement) N Facilitates transit Constructs elevated guideway in integration with E3 busway poor soils; increased potential maintained and business effects platform closer to Lander Holgate roadway Similar comparative overcrossing Maintains at-grade Lander estimate as ST3 eliminates light Street and gated at-grade Representative Project* rail/traffic conflicts crossing of existing light rail line 21 * Comparative estimate is + $200 M compared to Preferred Alternative (SODO At-Grade).
Initial assessment alternative 20 th Ave Tunnel Ballard N 22
Initial assessment alternatives 20 th Ave Tunnel Ballard – BNSF Portal 20 th Ave Tunnel Ballard – Thorndyke Portal (refinement) N 23
Description: 20 th Ave Tunnel Ballard — BNSF Portal Tunnel portal in Tunnel station at 20 th Elevated over BNSF property BNSF tracks Longer tail tracks Tunnel under Salmon Bay Elevated Interbay station at Dravus N 24
Key considerations: 20 th Ave Tunnel Ballard – BNSF Portal Station at 20 th closer to core May require relocation of Requires relocation of very of Ballard Hub Urban Village some BNSF operations large underground utilities adding potential constructability challenges Greater potential Shorter tunnel residential under Salmon Bay effects Requires long Greater potential construction span over effects, property constraints/effects, BNSF tracks and constructability challenges in Ballard core Requires 3 rd Party funding (+ $750 M*) N 25 * Compared to ST3 Representative Project
Description: 20 th Ave Tunnel Ballard – Thorndyke Portal (refinement) Tunnel under Interbay station in Salmon Bay Tunnel station at 20 th trench at Dravus Tunnel portal north of Interbay Station N 26
Key considerations: 20 th Ave Tunnel Ballard – Thorndyke Portal (refinement) Station at 20 th closer to core Requires relocation of large underground utilities adding of Ballard Hub Urban Village potential constructability challenges Greater potential construction effects, property constraints/effects, Longer tunnel and constructability challenges in under Salmon Bay Ballard core Potential retrofit or reconstruction of Dravus and Emerson bridges, adds Requires 3 rd Party funding engineering complexity and risk (+ $450 M*) N 27 * Compared to ST3 Representative Project
Comparative estimates and schedule Comparison to ST3 Representative Project Initial assessment alternative Comparative Estimate (2018$) Schedule Yancy/Andover Elevated Similar Similar Requires 3 rd Party funding (+$900 M*) Pigeon Point Tunnel* Schedule risk SODO Elevated Requires 3 rd Party funding (+$300 M) Similar SODO Double Elevated SODO Partial Elevated Similar Similar 20 th Ave Tunnel Ballard Requires 3 rd Party funding (+$750 M) Similar 20 th Ave Tunnel Ballard - BNSF Portal 20 th Ave Tunnel Ballard - Thorndyke Portal Requires 3 rd Party funding (+$450 M) Similar * Pigeon Point Tunnel Alternative connects to West Seattle Junction Tunnel stations only. 28 Comparative estimate includes +$200 M for Pigeon Point Tunnel and +$700 M for West Seattle Junction Tunnel.
Schedule and next steps
Initial assessment timeline Sound Transit Board Sept. 12 Initial Assessment evaluation results and next steps System Expansion Committee Evaluation Information Online Sept. 13 – Oct. 4 Initial Assessment evaluation results and next steps Comment form / Community briefings Sound Transit Board Sept. 26 Initial Assessment evaluation results and next steps Full Board Sound Transit Board Initial Assessments – potential action Oct. 10 System Expansion Committee Establish whether further study in DEIS is appropriate Sound Transit Board Initial Assessments – potential action Oct. 24 Full Board Establish whether further study in DEIS is appropriate 30
Environmental Review 2019 2020 2021 WE ARE HERE Q3 Q4 Q1 Q2 Q3 Q4 Q1 EIS kickoff…………………. Conceptual Engineering ……… Develop DEIS ………………….. Station planning activities …………… ST Board confirms or modifies Publish DEIS and public Preferred Alternative comment period ………………….………………….………………….……………. Schedule risk if alternatives added 31
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