7a Presentation ST3

Item No.          7a_supp 
Update on ST3   Date of Meeting  September 25, 2018 
West Seattle and Ballard Link
Extensions 
Level 2 Screening Results 
September 25, 2018 

1

Primary Port of Seattle Objectives
for ST3 Projects 
1.   Improve regional transportation for personal mobility, while protecting
maritime and industrial land uses and freight mobility; 
2.   Strengthen access to POS/NWSA facilities, both existing and future
developments; and 
3.   Enhance service to Seattle-Tacoma International Airport for passengers
and employees, from a web of cities throughout the region. 

2

System expansion 
Sound Transit's system expansion means
every few years new light rail, bus rapid
transit and commuter rail stations open
throughout the region, providing fast, 
reliable alternatives to congested roads. 

soundtransit.org/system

ST3 Representative
project 
Identifies mode, corridor,
number of stations, general
station locations 
Informs cost, schedule,
operating needs 


4

West Seattle 
Link Extension 
Opening 2030 
Four elevated stations at SODO,
Delridge, Avalon and Alaska
Junction; one at-grade station at
Stadium 
New rail-only fixed span crossing
of the Duwamish River 
Length: 4.7 miles

Ballard Link
Extension 
Opening 2035 
Three elevated stations: Ballard,
Interbay, Smith Cove 
Six tunnel stations: Seattle Center,
South Lake Union, Denny, Westlake,
Midtown, International
District/Chinatown 
New rail-only movable bridge over
Salmon Bay 
Length: 7.1 miles

West Seattle project timeline 
PLANNING       DESIGN      CONSTRUCTION   START OF 
20172022                20222025                         20252030     SERVICE 
2016                                                                                           2030 
Alternatives development       Final route design              Conversations with 
property owners 
Board identifies preferred       Final station designs 
alternative                                                      Groundbreaking 
Procure and commission
Draft Environmental            station and public art           Construction updates 
Impact Statement                                            and mitigation 
Obtain land use and
Final Environmental            construction permits            Safety education 
Impact Statement 
Testing and pre-operations 
Board selects project 
to be built 
Federal Record of
Decision 

PUBLIC INVOLVEMENT      PUBLIC INVOLVEMENT          PUBLIC INVOLVEMENT

Ballard project timeline 
PLANNING       DESIGN      CONSTRUCTION   START OF 
20172022                20232026                         20272035     SERVICE 
2016                                                                                           2035 
Alternatives development       Final route design              Conversations with 
property owners 
Board identifies preferred       Final station designs 
alternative                                                      Groundbreaking 
Procure and commission
Draft Environmental            station and public art           Construction updates 
Impact Statement                                            and mitigation 
Obtain land use and
Final Environmental            construction permits            Safety education 
Impact Statement 
Testing and pre-operations 
Board selects project 
to be built 
Federal Record of
Decision 

PUBLIC INVOLVEMENT      PUBLIC INVOLVEMENT          PUBLIC INVOLVEMENT

PLANNING     DESIGN 
2016 
20172019       20192022 
Alternatives              Draft Environmental
development            Impact Statement 
Board identifies          Final Environmental
preferred alternative      Impact Statement 
Board selects project
to be built 
Federal Record of
Decision 
PUBLIC INVOLVEMENT

Alternatives development process 
LEVEL 1        LEVEL 2         LEVEL 3    PREFERRED 
Alternatives development      Alternatives development       Alternatives development      ALTERNATIVE* 
Early-2018                       Mid-2018                       Late-2018 / Early-2019           Early-2019 
Conduct early scoping            Technical analysis                Refine and screen
alternatives 
Study ST3 representative        Refine and screen
project and alternatives            alternatives                        Conduct Environmental
Impact Statement 
Screen alternatives                                                  (EIS) scoping 

PUBLIC INVOLVEMENT       PUBLIC INVOLVEMENT       PUBLIC INVOLVEMENT 

*The Sound Transit Board identifies preferred alternatives and other alternatives to study.

Screening process 
Broad range of initial
alternatives 
Refine remaining
alternatives 

Further 
evaluation 
Preferred Alternative and
other EIS alternatives 
11

Community Engagement
and Collaboration 
12

Community engagement and collaboration 



13

Overview 
Early scoping: Feb. 2  March 5 
Notification via postcards,
advertisements, project website,
email updates, press releases,
social media, agency invitation
letters, etc. 
3 public meetings in Feb. 
Online open house 
1 agency meeting 
Other methods to comment 
14

Neighborhood forums 
4/21: Chinatown / Int'l District 
4/23: Denny / SLU / Seattle Center 
5/2: Midtown / Westlake 
5/5: Delridge / Avalon / Alaska Junction 
5/9: SODO / Stadium 
5/12: Ballard / Interbay / Smith Cove 

15

External Engagement Report: Jun-Aug 2018 
engaging more than 
17 comments and questions            8 festivals   3,300 community members 
email     engaging more than 
6 updates  4,000 subscribers             49 community briefings 
4 Tweets engaging 82,000 users 
more than                                              2 
Stakeholder Advisory Group meetings 
5 posts                                 1
engaging 30,000 users                   Elected Leadership Group meeting 
more than 

16

Station Charrettes 
Collaborative design sessions with
agencies, key community stakeholders 
6/28: Ballard / Interbay 
7/12: Seattle Center 
7/20: Delridge 
7/24: Alaska Junction / Avalon 
7/30: Chinatown  International District 
8/2: Denny / SLU 
8/28 SODO/Stadium 
17

Level 2 alternatives
evaluation 
18

Purpose and need 
Purpose Statement                                                 Symbol 
Provide high quality rapid, reliable, and efficient peak and off-peak LRT service to communities in the
project corridors as defined in ST3. 

Improve regional mobility by increasing connectivity and capacity through downtown Seattle to meet the
projected transit demand. 

Connect regional centers as described in adopted regional and local land use, transportation, and
economic development plans and Sound Transit's Regional Transit Long-Range Plan. 

Implement a system that is consistent with the ST3 Plan that established transit mode, corridor, and
station locations and that is technically feasible and financially sustainable to build, operate, and maintain. 

Expand mobility for the corridor and region's residents, which include transit dependent, low income, and
minority populations. 
Encourage equitable and sustainable urban growth in station areas through support of transit-oriented
development, station access, and modal integration in a manner that is consistent with local land use
plans and policies. 
Preserve and promote a healthy environment and economy by minimizing adverse impacts on the
natural, built and social environments through sustainable practices. 
19

Evaluation criteria 
17 criteria consistent in all levels of evaluation 
Reliable service                      Financial sustainability 
Travel times                         Historically underserved populations 
Regional connectivity                Station area local land use plan
Transit capacity                       consistency 
Projected transit demand            Modal integration 
Regional centers served             Station area development opportunities 
ST Long-Range Plan consistency    Environmental effects 
ST3 consistency                    Traffic operations 
Technical feasibility                    Economic effects 
20

Measures and methods 
50+ quantitative and/or qualitative measures 
Rating thresholds for High, Medium and Low 
Key differentiators and findings 

Lower              Medium              Higher 
Performing             Performing             Performing 

21

Cost assessment 
Purpose: To inform comparison of Level 2 alternatives 
Comparative costs by segment 
Consistent methodology (2017$; construction, real estate, etc.) 
Based on limited conceptual design (less than 5% design) 
Final project budget established at 60% design (~ 2024) 
Costs for end-to-end alternatives in Level 3 
22

Financial constraints 
ST3 Plan budget based on 2014 conceptual cost estimates 
Significant recent escalation in construction and real estate
costs 
Level 2 cost assessment provides basis for comparison of
alternatives within a segment 
Level 3 end-to-end alternatives will facilitate comparison to
ST3 budget 
Be mindful of financial realities when considering Level 2
recommendations 
23

West Seattle/
Duwamish 


Interbay/Ballard 

Downtown 
SODO and
Chinatown/ID 
Study segments 
24

1     2 
Map of alternatives                     Evaluation measures 
3     4 
Key differentiators                           Summary 
25

Level 2 alternatives 
Interbay/Ballard 

ST3 Representative Project 
15th/Fixed Bridge/15th 
20th/Fixed Bridge/17th 
20th/Tunnel/15th 
Armory Way/Tunnel/14th 
Central Interbay/Movable Bridge/14th 
Central Interbay/Fixed Bridge/14th 
Central Interbay/Tunnel/15th 

26

Interbay/Ballard 
Level 2 alternatives                                                                      27

Central Interbay/
ST3 Representative 15th/Fixed Bridge/  20th/Fixed Bridge/    20th/Tunnel/                        Armory Way/    Central Interbay/   Central Interbay/
Evaluation Measures                                                                                Movable Bridge/
Project             15th              17th              15th                            Tunnel/14th     Fixed Bridge/14th     Tunnel/15th 
14th 
Provide high quality rapid, reliable, and efficient peak and off-peak light rail transit service to communities in the project corridors defined in ST3. 
Potential Service Interruptions           Lower             Higher            Higher            Higher             Lower             Higher            Higher            Higher 
Travel Times (minutes)               5 to 6             5 to 6             5 to 6             5 to 6             5 to 6             5 to 6             5 to 6             5 to 6 
Improve regional mobility by increasing connectivity and capacity through downtown Seattle to meet projected transit demand. 
Network Integration               Medium           Medium           Medium           Medium           Medium           Medium           Medium           Medium 
Passenger Carrying Capacity           Medium           Medium           Medium           Medium           Medium           Medium           Medium           Medium 
Ridership Potential (2040 pop/emp) (1)        17,200            16,700            19,000            17,800            15,400            16,400            15,400            16,500 
Connect regional centers as described in adopted regional and local land use, transportation, and economic development plans and Sound Transit's Long-Range Plan. 
Regional Growth Centers Served          N/A (3)              N/A               N/A               N/A               N/A               N/A               N/A               N/A 
Manufacturing/Industrial Centers Served         1                 1                 1                 1                 1                 1                 1                 1 
Accommodates Future LRT Extension        Medium           Medium            Lower            Higher           Medium           Higher           Medium           Higher 
Implement a system that is consistent with the ST3 Plan that established transit mode, corridor, and station locations and that is technically feasible and financially sustainable to build, operate, and maintain. 
Mode, Route and Stations per ST3         Higher            Higher            Higher            Higher            Higher            Higher            Higher            Higher 
Potential ST3 Schedule Effects           Higher            Higher            Higher            Higher            Higher            Higher            Higher            Higher 
Potential ST3 Operating Plan Effects         Lower             Higher            Higher            Higher             Lower             Higher            Higher            Higher 
Engineering Constraints             Medium           Medium           Medium            Lower             Higher             Lower             Higher             Lower 
Constructability Issues              Medium           Medium           Medium            Lower             Higher             Lower             Higher             Lower 
Operational Constraints              Lower             Higher            Higher            Higher             Lower             Higher            Higher            Higher 
Conceptual Capital Cost Comparison           -           $200M increase     $500M increase     $700M increase     $200M increase     $300M increase     $100M increase     $500M increase 
Operating Cost Impacts             Medium           Medium           Medium           Medium           Medium           Medium           Medium           Medium 
Expand mobility for the corridor and region's residents, which include transit dependent, low income, and minority populations. 
Opportunities for Low-Income/Minority       Medium           Medium           Medium           Medium           Medium           Medium           Medium           Medium 
(activity nodes/subsidized rental units) (1)        8%               9%               8%               8%               8%               8%               8%               9% 
Low-Income Population (1/2)           19% / 18%         20% / 18%         20% / 18%         20% / 18%         19% / 18%         19% / 18%         19% / 18%         19% / 18% 
Minority Population (1/2)            21% / 20%         21% / 20%         21% / 20%         21% / 20%         21% / 20%         21% / 20%         21% / 20%         21% / 20% 
Youth Population (1/2)              9% / 12%          11% / 12%         11% / 12%         11% / 12%         12% / 12%         11% / 12%         12% / 12%         10% / 12% 
Elderly Population (1/2)             10% / 10%         10% / 10%         10% / 10%         10% / 10%          9% / 10%          9% / 10%          9% / 10%          10% / 10% 
Limited English Proficiency Population 
4% / 3%           4% / 3%           4% / 3%           4% / 3%           3% / 3%           3% / 3%           3% / 3%           3% / 3% 
(1/2) 
Disabled Population (1/2)             9% / 8%           9% / 8%           9% / 8%           9% / 8%           8% / 8%           8% / 8%           8% / 8%           9% / 8% 
(1) Within station walksheds 
(2) Within 15 minute ride on connecting high frequency transit                                                                                                       Medium
Lower Performing                        Higher Performing 
(3) NA = Measure not applicable to this segment                                                                                                               Performing 
Interbay/Ballard 
Level 2 alternatives evaluation  Part 1 of 2                                             28

Central Interbay/
ST3 Representative  15th/Fixed Bridge/  20th/Fixed Bridge/    20th/Tunnel/                         Armory Way/     Central Interbay/   Central Interbay/
Evaluation Measures                                                                                  Movable Bridge/
Project             15th              17th              15th                             Tunnel/14th      Fixed Bridge/14th      Tunnel/15th 
14th 
Encourage equitable and sustainable urban growth in station areas through support of transit-oriented development, station access, and modal integration in a manner that is consistent with local land use plans and
policies. 
Compatibility with Urban Centers/Villages (1)      Medium           Medium           Medium           Medium            Lower             Lower             Lower            Medium 
Station Land Use Plan Consistency           Medium           Medium           Medium           Medium           Medium           Medium           Medium           Medium 
Activity Nodes Served (1)                 26                32                36                33                24                23                24                35 
Passenger Transfers                Medium           Medium           Medium           Medium           Medium           Medium           Medium           Medium 
Bus/Rail and Rail/Rail Integration (1)           Higher            Medium           Medium            Higher             Higher             Higher             Higher             Higher 
Bicycle Accessibility (1)                Higher             Higher             Higher             Higher            Medium            Higher            Medium            Higher 
Pedestrian/Limited Mobility Accessibility (1)        Lower            Medium            Higher             Higher             Lower            Medium            Lower            Medium 
Development Potential (1)              Medium           Medium            Higher            Medium           Medium           Medium           Medium           Medium 
Equitable Development Opportunities          Lower             Higher             Lower             Lower            Medium           Medium           Medium            Higher 
Preserve and promote a healthy environment and economy by minimizing adverse impacts on the natural, built and social environments through sustainable practices. 
Historic Properties/Landmarks (2)              5                 7                 3                 3                 3                 2                 3                 3 
Potential for Effects to Archaeological Resources (1)       Lower             Lower             Lower             Lower             Lower             Lower             Lower             Lower 
Parks and Recreational Resources Effects (acres)         0.2                1                0.9                0.9                4.2                3.9                4.2                3.9 
Water Resource Effects (acres)              0.7                0.6                0                 0                0.7                0                0.4                0 
Fish and Wildlife Habitat Effects (acres)           11                11                0.5                0.5                1                11.4                1                0.5 
Hazardous Material Sites (2)                11                15                11                11                16                12                16                12 
Visual Effects                   Medium           Medium           Medium            Higher            Medium           Medium           Medium           Medium 
Noise and Vibration Sensitive Receivers (1)        Higher             Higher             Lower            Medium            Higher             Higher             Higher             Higher 
Potentially Affected Properties            Medium            Lower             Lower             Higher             Higher             Higher             Higher             Higher 
Residential Unit Displacements             Higher             Lower             Lower            Medium           Medium            Higher            Medium            Higher 
Square Feet of Business Displacements        Medium           Medium           Medium            Higher            Medium            Higher            Medium            Lower 
Construction Impacts                Lower            Medium            Lower            Medium            Higher             Higher             Higher            Medium 
Burden on Low-Income/Minority            Higher             Higher             Higher             Higher             Higher             Higher             Higher             Higher 
Traffic Circulation and Access Effects           Lower            Medium           Medium            Higher            Medium            Higher            Medium            Higher 
Effects on Existing Transportation Facilities       Medium            Higher             Lower            Medium           Medium            Higher            Medium           Medium 
Effects on Freight Movement              Lower            Medium           Medium           Medium           Medium            Higher            Medium            Higher 
Business and Commerce Effects            Lower             Lower            Medium            Higher            Medium            Higher            Medium           Medium 
(1) Within station walksheds and/or defined buffer of alignment 
Medium
(2) On properties that overlap with the project footprint                                                                                            Lower Performing                        Higher Performing 
Performing 
Interbay/Ballard 
Level 2 alternatives evaluation  Part 2 of 2                                             29

Salmon Bay Crossing 
Smith Cove-Interbay 
Ballard Terminus 


Interbay/Ballard 
Key differentiators  By sub-segment                                                 30

Smith Cove-Interbay: 
Key differentiators 
Station location 
Traffic 
Engineering constraints 

Interbay/Ballard 
Key differentiators  Smith Cove-Interbay                                             31

Key differentiators Smith Cove-Interbay 
Alternative                                      Key differentiators 
ST3 Representative 
Project 
15th/Fixed Bridge/15th                     Lessens traffic/freight effects (avoids 15th Ave median) 
20th/Fixed Bridge/17th 
Lessens traffic/freight effects (avoids 15th Ave) 
Long span bridge (over BNSF tracks) adds complexity 
20th/Tunnel/15th 
Central Interbay/ 
Movable Bridge/14th 
Armory Way/ 
Tunnel/14th                               Lessens traffic/freight effects (avoids 15th Ave) 
Central Interbay/                          At-grade sections (along BNSF tracks) lessen complexity 
Fixed Bridge/14th 
Central Interbay/ 
Tunnel/15th 
32

Salmon Bay Crossing: 
Key differentiators 
Crossing location 
Crossing type 
Bridge (fixed or movable) 
Tunnel 
Freight movement 
Business/commerce effects 
Interbay/Ballard 
Key differentiators  Salmon Bay Crossing                                           33

Key differentiators Salmon Bay Crossing 
Alternative                                       Key differentiators 
ST3 Representative 
Project 
Fewer columns in water than movable bridge 
15th/Fixed Bridge/15th 
Maritime business effects (Fishermen's Terminal) 
20th/Fixed Bridge/17th                      Long-span fixed bridge avoids columns in water 
Longer tunnel, more constrained portal 
20th/Tunnel/15th 
Includes tunnel; requires 3rd Party funding 
Central Interbay/                            Potential service interruptions 
Movable Bridge/14th                      Maritime business and potential vessel navigation effects 
Armory Way/                           Shorter tunnel, less constrained portal 
Tunnel/14th                                 Includes tunnel; requires 3rd Party funding 
Central Interbay/                            Fewer columns in water than movable bridge 
Fixed Bridge/14th                           Maritime business effects 
Central Interbay/                            Shorter tunnel, less constrained portal 
Tunnel/15th                                 Includes tunnel; requires 3rd Party funding 

34

Ballard Terminus: 
Key differentiators 
Ballard Station location 
Elevated or tunnel 

Interbay/Ballard 
Key differentiators  Ballard Terminus                                                  35

Key differentiators Ballard Terminus 
Alternative                                       Key differentiators 
ST3 Representative 
Project 
Elevated guideway (west side 15th Ave NW) affects more parcels 
15th/Fixed Bridge/15th 
More residential displacements 
Ballard terminus/crossing location affects more residences 
20th/Fixed Bridge/17th 
Closer to center of Urban Village 
Tunnel station (west side 15th Ave NW) affects residences 
20th/Tunnel/15th 
Deeper tunnel station (~120'); adds complexity 
Central Interbay/ 
Movable Bridge/14th 
Affects fewer parcels (along 14th Ave NW) 
Armory Way/ 
Farther from center of Urban Village 
Tunnel/14th 
Shallower tunnel station (~70') 
Central Interbay/ 
Fixed Bridge/14th 
Central Interbay/                           Tunnel station (east side 15th Ave NW) affects businesses 
Tunnel/15th                                Shallower tunnel station (~80') 
36

Summary Interbay/Ballard 
Cost         Schedule
Alternative                      Key findings 
comparison*   Comparison** 
ST3 Representative
Project 
Central Interbay/                    Maritime business effects (but less than movable bridge)                                                   Higher 
+ $100M 
Fixed Bridge/14th                   Affects fewer parcels in Ballard (along 14th Ave NW)                                                    Performing 
Potential service interruptions 
Central Interbay/                                                                                                                                  Higher 
Maritime business and potential vessel navigation effects                                 + $200M 
Movable Bridge/14th                                                                                                                    Performing 
Affects fewer parcels in Ballard (along 14th Ave NW) 
Maritime business effects (Fishermen's Terminal)                                                              Higher 
15th/Fixed Bridge/15th                                                                                                          + $200M 
Elevated guideway (west side 15th Ave NW) affects more residences                                       Performing 
Less environmental, maritime business/navigation effects 
Armory Way/                                                                                                            Higher 
Affects fewer parcels in Ballard (along 14th Ave NW)                                       + $300M 
Tunnel/14th                                                                                                                                   Performing 
Includes tunnel; requires 3rd Party funding 
Less environmental, maritime business/navigation effects 
Central Interbay/                                                                                                                                Higher 
Tunnel station (east side 15th Ave NW) affects businesses                                 + $500M 
Tunnel/15th                                                                                                                                   Performing 
Includes tunnel; requires 3rd Party funding 
Long span bridge (over BNSF tracks) adds complexity                                                         Higher 
20th/Fixed Bridge/17th                                                                                                          + $500M 
Ballard terminus/crossing location affects more residences                                                  Performing 
Long span bridge (over BNSF tracks), constrained tunnel portal location,
deeper tunnel station add complexity                                                                     Higher 
20th/Tunnel/15th                                                                                                                  + $700M 
Tunnel station (west side 15th Ave NW) affects residences                                                   Performing 
Includes tunnel; requires 3rd Party funding 
*Cost compared to cost of ST3 Representative Project for this segment. Schedule compared to overall ST3 schedule for this extension.                     37

Level 2 alternatives 
West Seattle/Duwamish 

ST3 Representative Project 
Pigeon Ridge/West Seattle
Tunnel 
Oregon Street/Alaska
Junction/Elevated 
Oregon Street/Alaska
Junction/Tunnel (new) 
Golf Course/Alaska
Junction/Tunnel (modified) 


38

West Seattle/Duwamish 
Level 2 alternatives                                                                      39

Pigeon Ridge/West Seattle   Oregon Street/Alaska Junction/ Golf Course/Alaska Junction/ Oregon Street/Alaska Junction/
Evaluation Measures             ST3 Representative Project 
Tunnel                     Elevated                     Tunnel                      Tunnel 
Provide high quality rapid, reliable, and efficient peak and off-peak light rail transit service to communities in the project corridors defined in ST3. 
Potential Service Interruptions                  Higher                      Higher                      Higher                      Higher                      Higher 
Travel Times (minutes)                     7 to 8                       7 to 8                       7 to 8                       7 to 8                       7 to 8 
Improve regional mobility by increasing connectivity and capacity through downtown Seattle to meet projected transit demand. 
Network Integration                     Medium                    Medium                    Medium                    Medium                    Medium 
Passenger Carrying Capacity                  Medium                    Medium                    Medium                    Medium                    Medium 
Ridership Potential (2040 pop/emp) (1)              11,200                      12,500                      12,000                      10,700                      12,500 
Connect regional centers as described in adopted regional and local land use, transportation, and economic development plans and Sound Transit's Long-Range Plan. 
Regional Growth Centers Served                 N/A (3)                       N/A                        N/A                        N/A                        N/A 
Manufacturing/Industrial Centers Served                1                          1                          1                          1                          1 
Accommodates Future LRT Extension               Lower                     Medium                     Lower                     Higher                     Medium 
Implement a system that is consistent with the ST3 Plan that established transit mode, corridor, and station locations and that is technically feasible and financially sustainable to build, operate, and maintain. 
Mode, Route and Stations per ST3                Higher                     Higher                     Higher                     Medium                     Higher 
Potential ST3 Schedule Effects                  Higher                      Lower                      Higher                      Lower                      Lower 
Potential ST3 Operating Plan Effects                Higher                      Higher                      Higher                      Higher                      Higher 
Engineering Constraints                    Medium                     Lower                     Medium                    Medium                     Higher 
Constructability Issues                     Lower                      Lower                      Lower                      Lower                     Medium 
Operational Constraints                    Medium                     Higher                     Medium                    Medium                    Medium 
Conceptual Capital Cost Comparison                  -                    $1,200M increase                 Similar                  $700M increase              $500M increase 
Operating Cost Impacts                     Higher                     Medium                     Higher                     Medium                    Medium 
Expand mobility for the corridor and region's residents, which include transit dependent, low income, and minority populations. 
Opportunities for Low-Income/Minority             Medium                    Medium                    Medium                    Medium                    Medium 
(activity nodes/subsidized rental units) (1)              15%                        13%                        14%                        15%                        13% 
Low-Income Population (1/2)                 25% / 21%                   24% / 21%                   23% / 21%                   26% / 21%                   23% / 21% 
Minority Population (1/2)                   22% / 26%                   23% / 26%                   21% / 26%                   23% / 26%                   21% / 26% 
Youth Population (1/2)                    13% / 17%                   14% / 17%                   14% / 17%                   13% / 17%                   14% / 17% 
Elderly Population  (1/2)                   16% / 13%                   15% / 13%                   15% / 13%                   16% / 13%                   15% / 13% 
Limited English Proficiency Population (1/2)            3% / 4%                     3% / 4%                     3% / 4%                     3% / 4%                     3% / 4% 
Disabled Population (1/2)                    9% / 9%                     9% / 9%                     9% / 9%                     9% / 9%                     9% / 9% 
(1) Within station walksheds 
Medium
(2) Within 15 minute ride on connecting high frequency transit                                                                                 Lower Performing                        Higher Performing 
Performing 
(3) NA = Measure not applicable to this segment 
West Seattle/Duwamish 
Level 2 alternatives evaluation  Part 1 of 2                                             40

Pigeon Ridge/West Seattle   Oregon Street/Alaska Junction/ Golf Course/Alaska Junction/ Oregon Street/Alaska Junction/
Evaluation Measures             ST3 Representative Project 
Tunnel                     Elevated                     Tunnel                     Tunnel 
Encourage equitable and sustainable urban growth in station areas through support of transit-oriented development, station access, and modal integration in a manner that is consistent with local land use
plans and policies. 
Compatibility with Urban Centers/Villages (1)           Medium                    Medium                    Medium                    Medium                     Lower 
Station Land Use Plan Consistency                Higher                      Higher                      Higher                      Higher                      Higher 
Activity Nodes Served (1)                      40                         41                         42                         38                         42 
Passenger Transfers                     Medium                     Higher                     Medium                    Medium                     Higher 
Bus/Rail and Rail/Rail Integration (1)               Medium                     Higher                     Medium                    Medium                     Higher 
Bicycle Accessibility (1)                     Higher                      Higher                      Higher                      Higher                      Higher 
Pedestrian/Limited Mobility Accessibility (1)            Medium                     Higher                      Higher                      Higher                      Higher 
Development Potential (1)                   Medium                    Medium                    Medium                     Higher                     Medium 
Equitable Development Opportunities               Lower                      Lower                     Medium                    Medium                     Higher 
Preserve and promote a healthy environment and economy by minimizing adverse impacts on the natural, built and social environments through sustainable practices. 
Historic Properties/Landmarks (2)                   1                          1                          1                          1                          2 
Potential for effects to Archaeological Resources (1)            Lower                      Lower                      Lower                      Lower                      Lower 
Parks and Recreational Resources Effects (acres)              1.5                         3.5                         1.5                         2.8                         0.6 
Water Resource Effects (acres)                  < 0.1                       < 0.1                       < 0.1                       < 0.1                       < 0.1 
Fish and Wildlife Habitat Effects (acres)                3.7                         5.3                         3.7                         3.7                         1.9 
Hazardous Materials Sites (1)                    11                          7                          8                          14                         14 
Visual Effects                         Lower                     Medium                     Lower                     Medium                    Medium 
Noise and Vibration Sensitive Receivers (1)             Lower                      Lower                      Lower                     Medium                     Lower 
Potentially Affected Properties                  Higher                      Higher                      Lower                      Higher                      Lower 
Residential Unit Displacements                 Medium                     Lower                      Lower                      Higher                      Lower 
Square Feet of Business Displacements              Higher                     Medium                     Lower                      Higher                     Medium 
Construction Impacts                     Lower                      Higher                      Lower                     Medium                    Medium 
Burden on Low-Income/Minority                 Higher                      Higher                      Higher                      Higher                      Higher 
Traffic Circulation and Access Effects               Lower                      Higher                     Medium                     Higher                     Medium 
Effects on Existing Transportation Facilities             Lower                      Higher                     Medium                    Medium                     Higher 
Effects on Freight Movement                  Medium                    Medium                    Medium                    Medium                     Lower 
Business and Commerce Effects                 Medium                     Higher                      Lower                     Medium                    Medium 
(1) Within station walksheds and/or defined buffer of alignment 
Medium
(2) On properties that overlap with the project footprint                                                                                     Lower Performing                        Higher Performing 
Performing 
West Seattle/Duwamish 
Level 2 alternatives evaluation  Part 2 of 2                                             41

Avalon-Genesee-         Duwamish Crossing 
Delridge 

Alaska Junction 


West Seattle/Duwamish 
Key differentiators  By sub-segment                                                 42

Duwamish Crossing: 
Key differentiators 
Crossing location 
Engineering constraints 
Fish and wildlife effects 
Freight movement 

West Seattle/Duwamish 
Key differentiators  Duwamish Crossing                                            43

Key differentiators Duwamish Crossing 
Alternative                                                Key differentiators 
ST3 Representative Project 

Bridge crossing near Idaho Street; south of Harbor Island 
Most engineering constraints (tunnel through unstable slopes, widest water
Pigeon Ridge / West Seattle Tunnel 
crossing, wide Union Pacific Argo railyard crossing, high voltage lines etc.) 
Most effects to Duwamish Greenbelt 

Oregon Street / Alaska Junction / Elevated 
Bridge crossing on south side of West Seattle bridge 
Some engineering constraints (Pigeon Point steep slope) 
Some effects to Duwamish Greenbelt (Pigeon Point) 
Golf Course / Alaska Junction / Tunnel 

Bridge crossing on north side of West Seattle bridge 
Fewer engineering constraints (avoids Pigeon Point steep slope) 
Oregon Street / Alaska Junction / Tunnel 
Avoids effects to Duwamish Greenbelt 
Affects freight, port terminal facilities during construction 
44

Summary West Seattle / Duwamish 
Cost           Schedule 
Alternative                                        Key findings 
comparison*      comparison* 
ST3 Representative Project 
3 elevated stations 
Increases residential/business effects at Junction                                           Higher 
Oregon Street / Alaska Junction / Elevated                                                                                  Similar 
Complicates future extension south                                                        Performing 
High guideway along Genesee 
1 tunnel station; 2 elevated stations 
High guideway along Genesee 
Lower 
Oregon Street / Alaska Junction / Tunnel               Fewer engineering constraints                                     + $500M 
Performing 
Affects freight, port terminal facilities during construction 
Includes tunnel; requires 3rd Party funding 
2 tunnel stations; 1 elevated station 
Lessens residential/business effects at Junction                                            Lower 
Golf Course / Alaska Junction / Tunnel                                                                                    + $700M 
Low guideway along Genesee                                                            Performing 
Includes tunnel; requires 3rd Party funding 
2 tunnels; 2 tunnel stations; 1 elevated station 
Most engineering constraints 
Most effects to Duwamish Greenbelt                                                        Lower
Pigeon Ridge / West Seattle Tunnel                                                                                   + $1,200M 
Low guideway along Genesee                                                            Performing 
Lessens residential and business effects in Delridge 
Includes two tunnels; requires 3rd Party funding 
*Cost compared to cost of ST3 Representative Project for this segment. Schedule compared to overall ST3 schedule for this extension. 
45

Level 2 alternatives 
SODO/Chinatown-ID 

ST3 Representative Project 
Massachusetts Tunnel Portal 
Surface E-3 
4th Avenue Cut-and-Cover C-ID 
4th Avenue Mined C-ID 
5th Avenue Mined C-ID 
Occidental Avenue 


46

ST3 Representative Project 

Massachusetts Tunnel Portal 


Surface E-3 
SODO and Chinatown-ID 
Level 2 alternatives  1 of 3                                                               47

4th Avenue Cut-and-Cover C-ID 

4th Avenue Mined C-ID 


5th Avenue Mined C-ID 
SODO and Chinatown-ID 
Level 2 alternatives  2 of 3                                                               48

Occidental Avenue


SODO and Chinatown-ID 
Level 2 alternatives  3 of 3                                                               49

ST3 Representative  Massachusetts Tunnel                     4th Avenue Cut-and-
Evaluation Measures                                                       Surface E-3                         4th Avenue Mined C-ID 5th Avenue Mined C-ID  Occidental Avenue 
Project               Portal                                 Cover C-ID 
Provide high quality rapid, reliable, and efficient peak and off-peak light rail transit service to communities in the project corridors defined in ST3. 
Potential Service Interruptions               Lower              Medium              Higher               Lower               Lower              Medium              Higher 
Travel Times (minutes)                  3 to 4               3 to 4               3 to 4               3 to 4               3 to 4               3 to 4               3 to 4 
Improve regional mobility by increasing connectivity and capacity through downtown Seattle to meet projected transit demand. 
Network Integration                  Medium             Medium              Higher              Medium             Medium             Medium             Medium 
Passenger Carrying Capacity               Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Ridership Potential (2040 pop/emp) (1)           35,900               35,900               35,900               35,300               35,300               35,900               37,100 
Connect regional centers as described in adopted regional and local land use, transportation, and economic development plans and Sound Transit's Long-Range Plan. 
Regional Growth Centers Served              N/A (3)                N/A                 N/A                 N/A                 N/A                 N/A                 N/A 
Manufacturing/Industrial Centers Served            1                   1                   1                   1                   1                   1                   1 
Accommodates Future LRT Extension           Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Implement a system that is consistent with the ST3 Plan that established transit mode, corridor, and station locations and that is technically feasible and financially sustainable to build, operate, and maintain. 
Mode, Route and Stations per ST3            Higher              Higher              Higher              Higher              Higher              Higher              Medium 
Potential ST3 Schedule Effects              Higher               Higher               Higher               Lower               Lower              Medium              Higher 
Potential ST3 Operating Plan Effects           Medium             Medium              Higher               Higher               Lower              Medium              Higher 
Engineering Constraints                Medium             Medium             Medium              Lower               Lower              Medium              Lower 
Constructability Issues                 Medium             Medium             Medium              Lower               Lower              Medium              Lower 
Operational Constraints                Medium             Medium              Higher              Medium              Lower              Medium             Medium 
Similar 
Conceptual Capital Cost Comparison              -             $200M decrease       $400M decrease       $600M increase       $500M increase           Similar 
(+ $200M in SODO) 
Operating Cost Impacts                 Medium             Medium              Higher              Medium             Medium             Medium             Medium 
Expand mobility for the corridor and region's residents, which include transit dependent, low income, and minority populations. 
Opportunities for Low-Income/Minority           Higher               Higher               Higher               Higher               Higher               Higher               Higher 
(activity nodes/subsidized rental units) (1)           80%                 80%                 80%                 75%                 75%                 80%                 73% 
Low-Income Population (1/2)              59% / 49%            59% / 49%            59% / 49%            57% / 49%            57% / 49%            59% / 49%            58% / 49% 
Minority Population (1/2)               65% / 54%            65% / 54%            65% / 54%            63% / 54%            63% / 54%            65% / 54%            65% / 53% 
Youth Population (1/2)                  7% / 7%              7% / 7%              7% / 7%              6% / 7%              6% / 7%              7% / 7%              7% / 8% 
Elderly Population  (1/2)                20% / 19%            20% / 19%            20% / 19%            20% / 19%            20% / 19%            20% / 19%            20% / 19% 
Limited English Proficiency Population (1/2)        30% / 19%            30% / 19%            30% / 19%            28% / 19%            28% / 19%            30% / 19%            30% / 18% 
Disabled Population (1/2)               24% / 19%            24% / 19%            24% / 19%            25% / 19%            25% / 19%            24% / 19%            24% / 19% 
(1) Within station walksheds 
(2) Within 15 minute ride on connecting high frequency transit                                                                                                         Medium
Lower Performing                        Higher Performing 
(3) NA = Measure not applicable to this segment                                                                                                                 Performing 
SODO and Chinatown-ID 
Level 2 alternatives evaluation  Part 1 of 2                                             50

ST3 Representative  Massachusetts Tunnel                     4th Avenue Cut-and-
Evaluation Measures                                                        Surface E-3                         4th Avenue Mined C-ID 5th Avenue Mined C-ID  Occidental Avenue 
Project               Portal                                 Cover C-ID 
Encourage equitable and sustainable urban growth in station areas through support of transit-oriented development, station access, and modal integration in a manner that is consistent with local land use plans and
policies. 
Compatibility with Urban Centers/Villages (1)         Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Station Land Use Plan Consistency              Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Activity Nodes Served (1)                    57                  57                  57                  54                  54                  57                  56 
Passenger Transfers                    Higher              Medium             Medium             Medium              Lower               Lower              Medium 
Bus/Rail and Rail/Rail Integration (1)             Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Bicycle Accessibility (1)                    21%                 21%                 21%                 21%                 21%                 21%                21% 
Pedestrian/Limited Mobility Accessibility (1)          Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Development Potential (1)                   14%                 14%                 14%                 13%                 13%                 14%                15% 
Equitable Development Opportunities             Lower              Medium              Lower              Medium              Lower              Medium              Higher 
Preserve and promote a healthy environment and economy by minimizing adverse impacts on the natural, built and social environments through sustainable practices. 
Historic Properties/Landmarks (2)                 3                   2                   3                   5                   2                   3                   3 
Potential for effects to Archaeological Resources(1)          Lower               Lower               Lower               Lower               Lower               Lower               Lower 
Parks and Recreational Resources Effects (acres)           0                   0                   0                   0                   0                   0                   0 
Water Resource Effects (acres)                  0                   0                   0                   0                   0                   0                   0 
Fish and Wildlife Habitat Effects (acres)              0                   0                   0                   0                   0                   0                   0 
Hazardous Materials Sites (1)                   4                   9                   4                   5                   9                   9                   6 
Visual Effects                       Higher               Higher               Higher               Higher               Higher               Higher               Higher 
Noise and Vibration Sensitive Receivers (1)          Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Potentially Affected Properties               Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Residential Unit Displacements               Medium             Medium             Medium             Medium             Medium             Medium             Medium 
Square Feet of Business Displacements            Higher               Lower               Higher               Lower               Higher               Lower               Lower 
Construction Impacts                   Lower               Higher              Medium              Lower               Lower               Higher              Medium 
Burden on Low-Income/Minority              Medium             Medium             Medium              Lower               Lower               Higher              Medium 
Traffic Circulation and Access Effects             Medium              Higher              Medium              Lower              Medium              Higher              Medium 
Effects on Existing Transportation Facilities           Lower               Higher              Medium              Lower               Lower               Higher              Medium 
Effects on Freight Movement                Medium              Higher              Medium              Lower               Lower               Higher               Lower 
Business and Commerce Effects              Medium             Medium             Medium             Medium             Medium              Higher               Lower 
(1) Within station walksheds and/or defined buffer of alignment 
(2) On properties that overlap with the project footprint                                                                                                                Medium
Lower Performing                        Higher Performing 
Performing 
SODO and Chinatown-ID 
Level 2 alternatives evaluation  Part 2 of 2                                             51

SODO                  Chinatown-ID 



SODO and Chinatown-ID 
Key differentiators  By sub-segment                                                 52

Summary SODO 
Cost          Schedule 
Alternative                     Key findings 
comparison*    comparison* 
ST3 Representative
Project 

New at-grade SODO Station on E-3 transitway at Lander                                                        Higher 
Surface E-3                                                                                                          - $100M 
Transfer at existing SODO Station                                                                               Performing 
Bus operations on E-3 transitway displaced 
New grade-separated roadway crossings (Lander, Holgate) improve
existing rail/traffic/freight operations 
Massachusetts                 Property effects at tunnel portal site (for Massachusetts Tunnel Portal                                  Higher 
** 
Tunnel Portal                    alternative only)                                                                                 Performing 
Massachusetts Tunnel Portal alternative avoids impacts to Ryerson Base 

New elevated SODO Station on Occidental Ave at Lander 
Transfer at existing Stadium Station 
Long span bridges over BNSF tracks and longer track connection to maintenance 
Higher 
Occidental Ave.                   facility                                                                                  + $200M 
Performing 
Bus operations on E-3 transitway partially displaced 
Property effects along Occidental, BNSF crossings and maintenance
facility connection 

*Cost compared to cost of ST3 Representative Project for this SODO sub-segment only. Schedule compared to overall ST3 schedule for this extension. 
**Cost comparison reflected in Chinatown/ID summary table. 
53

Summary Chinatown-ID 
Cost        Schedule 
Alternative                            Key findings 
comparison*   comparison* 
ST3 Representative 
Project 
E-3 Surface 
Shallow cut-and-cover station under 5th Ave; easy rider access/transfers                            Higher 
(shorter 5th Ave Cut-and-                                                                                                   - $300M** 
Construction effects, lane closures on 5th Ave in station area                                      Performing 
Cover Tunnel) 
Massachusetts Tunnel Portal             Shallow cut-and-cover station under 5th Ave; easy rider access/transfers                        Higher 
- $200M 
(5th Ave Bored Tunnel)                    Construction effects, lane closures on 5th Ave in station area                                   Performing 
Deep mined station (~200') under 5th Ave; poor rider access/transfers 
Less construction effects, lane closures on 5th Ave with mined station                                Medium 
5th Ave Mined C-ID                                                                                                  Similar 
Some property effects (for mined station access shaft)                                             Performing 
Results in very deep Midtown Station (~250') 
Deep mined station (~200') under 4th Ave, poor rider access/transfers 
Major engineering/constructability constraints (4th Ave viaduct
demolition/rebuild, active BNSF railway, existing transit tunnel, etc.)                              Lower 
4th Ave Mined C-ID                                                                                                 + $500M 
Large property effects (Ryerson Base for tunnel portal site)                                        Performing 
Requires 3rd party funding of 4th Ave Viaduct re-build costs 
Results in very deep Midtown Station (~250') 
Shallow cut-and-cover station under 4th Ave; easy rider access/transfers 
Major engineering/constructability constraints (4th Ave viaduct
Lower 
4th Ave Cut-and-Cover C-ID               demolition/rebuild, active BNSF railway, existing transit tunnel, etc.)           + $600M 
Performing 
Large property effects (King County Admin Building) 
Requires 3rd party funding of 4th Ave Viaduct re-build costs 
*Cost compared to cost of ST3 Representative Project for this segment. Schedule compared to overall ST3 schedule for this extension. 
**Cost comparison for Chinatown/ID sub-segment only; total SODO/C-ID segment cost difference is - $400M compared to ST3 Representative Project.                 54

Key POS, NWSA Evaluation
Criteria and Measures 
Economic Effects                          Transportation Operations 
Freight movement and access on               Traffic circulation and access 
land and water                             Transportation facilities 
Business and commerce effects 
Environmental Effects 
Regional Mobility                          Water resources 
Transit connectivity                           Property acquisitions and
displacements 
Ridership demand 
Construction impacts 
Possible impacts to operations and facilities 
55



Homeport to the Alaska fishing fleet & a vibrant commercial destination 
6,419 Local jobs and $449 million in business revenue

Terminal 91 


Blends fishing and cruise operations throughout the year 
Cruise ship homeport generates $2.7 million and provides over 4,000 jobs

International Container Trade 

Marine cargo operations provides $379 million in state and local taxes 
Nearly $4.3 billion in economic activity and more than 48,000 jobs 
58

Key Dates 
Stakeholder Advisory Group Level 2 recommendations  September 26 
Elected Leadership Group (ELG) Level 2 recommendations  October 5 
EIS scoping period  February 2019 
SEPA process expected 2019 - 2022 
ELG preferred alternative recommendation  March 22, 2019 
ST Board identification of preferred alternative  April 2019 

59

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