COMMISSION 
AGENDA MEMORANDUM                        Item No.          8b 
ACTION ITEM                            Date of Meeting      January 22, 2019 
DATE:     January 14, 2019 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Michael Ehl, Director Airport Operations 
Wayne Grotheer, Director Aviation Project Management 
SUBJECT:  Widen Arrivals Roadway (CIP #C800866)  Design 
Amount of this request:                    $8,340,000 
Total estimated project cost:              $50,000,000 
ACTION REQUESTED 
Request Commission authorization for the Executive Director, in support of the Widen Arrivals
Roadway project located at Seattle-Tacoma International Airport, to 1) amend a project-specific
design contract to increase the contract value by $2,600,000, 2) proceed with the design and
preparation of contract bid documents, 3) execute utility agreements, and 4) negotiate and
execute project labor agreements.  The amount being requested under this authorization is
$8,340,000 of a total estimated project cost of $50,000,000. 
EXECUTIVE SUMMARY 
The purpose of this project is to increase the capacity of the southbound lanes of the Northern
Airport Expressway, thereby addressing the key cause of congestion and queuing for vehicles
accessing the Main Terminal and Garage. The approved 2019 budget includes $15.6 million for
this project; this request totals $8.6 million and $2.1 million is expected to be expended in 2019
as design gets underway. The total estimated project cost has increased by $34.4 million to $50 
million in order to align the proposed scope with the improvements contemplated by the
Sustainable Airport Master Plan (SAMP)
Today's authorization request supports only the design phase of this work.Design will progress
at risk and will be contingent on the outcome of the SAMP Near-Term Projects environmental
review that is currently underway. Future budget increases and construction authorizations will
be phased in support of the work, and to address potential significant scope and cost increases 
associated with the Airport Utilities Master Plan. 
JUSTIFICATION 
This project supports the following Century Agenda strategic goals and objectives: 

Template revised April 12, 2018.

COMMISSION AGENDA  Action Item No. __8b__                              Page 2 of 8 
Meeting Date: January 22, 2019 
1)  Advance this region as a leading tourism destination and business gateway by meeting
the region's air transportation needs at the Airport for the next 25 years. 
2)  Be the greenest and most energy efficient  port in North America by meeting or
exceeding  agency requirements for storm water  leaving Port-owned or operated
facilities, and by reducing air pollutants and carbon emissions. 
3) Use the Port's influence as an institution to promote women and minority business
enterprise (WMBE) growth through Resolution 3737  Diversity in Contracting WMBE
aspirational goals, small business growth, and workforce development by increasing the
proportion of funds spent by the Port with qualified firms on construction, consulting, 
goods, and services. 
The terminal roadway system was originally designed in 1968 to support an overall activity level
of 25 million annual passengers (MAP).  Over the years, a number of efforts have been
completed to extend the life of the terminal roadway system.  These include; relocating
commercial ground transportation services to the third floor Ground Transportation Center and
Northeast Ground Transportation Lot, extending the Arrivals curbside to the south for public
transit and commercial ground transportation, and relocating rental car customers off-site to
the consolidated Rental Car Facility.
With the Airport reaching 47 MAP in 2017, the southbound lanes of the Northern Airport
Expressway, which provide access to the Main Terminal and Garage, are currently capacityconstrained
, resulting in significant congestion and queueing during peak periods. With no
further improvements, when airport passenger traffic reaches 54 MAP, studies have indicated
that peak period congestion and queueing during peak periods will reach the I-5/I-405 South 
Center interchange on a regular basis. This project is intended to address the existing capacity
constraints and provide the necessary roadway capacity and access in support of the strategies
under consideration in the Ground Transportation Access Plan (GTAP), and the anticipated use
of the Main Terminal and Garage as defined by the SAMP Near-Term projects.
DETAILS 
The Widen Arrivals Roadway project includes the widening of the southbound lanes of the
Northern Airport Expressway to provide an additional two lanes for a total of six lanes from
South 170th Street into the Departures and Arrivals curbsides and Main Garage. This requires
the relocation and expansion of the roadways to the west given the location of the columns
supporting the Light Rail Transit guideway. This project supports and accommodates the SAMP
Near-Term project to relocate the southbound lanes of the Northern Airport Expressway
required to prepare for the development of the Second Terminal by raising the existing
roadway grades. 
Design will progress at risk and will be contingent on the outcome of SAMP Near-Term Projects
environmental  review.  While  design  can  overlap  the  environmental  review  process, 
construction cannot start until both the State Environmental Policy Act (SEPA) Environmental
Impact  Statement  (EIS)  and  National  Environmental  Policy  Act  (NEPA)  Environmental

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __8b__                              Page 3 of 8 
Meeting Date: January 22, 2019 
Assessment (EA) are complete. The SAMP SEPA EIS/NEPA EA is anticipated to be complete by
early 2020 and the current project schedule does not require construction authorization until
Q4 2020. 
On April 24, 2018, the Commission authorized the Airport Utilities Master Plan; the Widen
Arrivals Roadway project includes several risks associated with the development of this plan.
The Airport Utilities Master Plan may result in decisions to build a utility corridor under the
Arrivals approach roadway or to upgrade the  primary water, storm drainage, or power 
distribution systems under the roadways. Due to the work associated with the Airport Utilities
Master Plan, the construction will occur in two phases, under two separate construction
contracts, to help mitigate these risks.  Phase I will provide the improvements necessary to
support the Phase II temporary roadways (detours), and Phase II will provide the temporary
roadways and permanent roadway improvements to support Airport operations.  Both the
Phase I and Phase II construction contracts will utilize project labor agreements. 
The total estimated cost to complete the Widen Arrivals Roadway project as currently defined
is $50 million. Since the  Airport Utilities Master Plan risks can be significant if they occur and
changes to the project are needed, they will be treated as scope revisions requiring additional
Commission authorization. Future requests for Commission authorizations, and corresponding
budget increases, are planned to coincide with the phased implementation of this project and
would include any scope revisions.
Scope of Work 
The Widen Arrivals Roadway project is a roadway improvement project.  These types of
projects generally include paving, sidewalks, barriers/curbs, pavement markings, illumination,
storm drainage, retaining walls, signage, sign structures, safety elements (e.g. attenuators), and
Intelligent Transportation Systems (ITS) improvements. Key components of the project include: 
(1)    The widening of the southbound lanes of the Northern Airport Expressway to provide
an additional two lanes into the curbsides and Main Garage 
(2)    The demolition of the existing closed bridge from Departures to the 4th Floor of the
Main Garage 
(3)    The demolition of the remaining Bridge 5 ramp and abutment, construction of a
retaining wall to support the Departures approach roadway, and the relocation of the
north rental car bus curb further to the north 
(4)    The completion of the seismic retrofit of the north portal of the Service Tunnel,
consistent with work underway in other portions of the tunnel 
(5)    The construction of a retaining wall along the airfield north of the Service Tunnel and
the relocation of power, water, and natural gas infrastructure systems to support the
future temporary roadways (detours) 
(6)    The relocation of a portion of Air Cargo Road along the new airfield retaining wall 


Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __8b__                              Page 4 of 8 
Meeting Date: January 22, 2019 
The project will be completed in two phases under two separate construction contracts. Phase
I includes; the Service Tunnel north portal seismic retrofit, the new airfield retaining wall, the
relocation of infrastructure systems to support the Phase II temporary roadways (detours), and
the relocation of a portion of Air Cargo Road.  Phase II includes; the construction of the
temporary roadways, the construction of the permanent approach roadways for the Main
Garage, Arrivals and Departures curbsides, and the other remaining scope elements. 
Schedule 
Design start                                            2019 Quarter 1 
Commission construction authorization (Phase I)      2020 Quarter 4 
Construction start (Phase I)                            2021 Quarter 2 
In-use date (Phase I)                                    2021 Quarter 4 
Commission construction authorization (Phase II)     2021 Quarter 4 
Construction start (Phase II)                            2022 Quarter 1 
In-use date (Phase II)                                   2023 Quarter 1 
Cost Breakdown                                      This Request           Total Project 
Design                                                  $8,340,000             $8,600,000 
Construction                                                     $0            $41,400,000 
Total                                                          $8,340,000             $50,000,000 
ALTERNATIVES AND IMPLICATIONS CONSIDERED 
Alternative 1  No improvements are completed until the SAMP Near-Term Project to relocate 
southbound lanes of the Northern Airport Expressway is implemented in support of the Second
Terminal 
Cost Implications: $0 
Pros: 
(1)   No significant capital investment in the short-term 
(2)   Allows the completion of the Airport Utilities Master Plan before beginning the design
for the roadway improvements 
Cons: 
(1)   Due to existing capacity constraints significant congestion and queueing occurs each
day on the southbound lanes of the Northern Airport Expressway.   With no
improvements, when airport passenger traffic reaches 54 MAP, studies have indicated
that the Expressway queueing will reach the I-5/I-405 South Center interchange on a
regular basis.  With the additional delay the project would be under construction
during these higher periods of congestion. 
This is not the recommended alternative. 

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __8b__                              Page 5 of 8 
Meeting Date: January 22, 2019 
Alternative 2  The southbound lanes of the Northern Airport Expressway and the approach to
the Arrivals curbside are widened to provide one more lane. 
Cost Implications: $18,200,000 
Pros: 
(1) Lower capital investment in the short-term 
(2) Provides the necessary capacity improvements in support of Airport Operations 
(3) Allows the completion of the Airport Utilities Master Plan before beginning the design of
the SAMP Near-Term projects 
Cons: 
(1) This alternative does not support, by raising the existing roadway grades, the SAMP
Near-Term projects.   The completed roadway improvements would need to be
reconstructed as part of the relocation of the southbound lanes of the Northern Airport
Expressway. 
(2) Greatest overall capital investment for the Airport's roadway improvements 
This is not the recommended alternative. 
Alternative  3    Provide  capacity  improvements  through  a  Heavy  Civil  General
Contractor/Construction Management (GC/CM) contract 
Cost Implications: $55,500,000 
Pros: 
(1)   Selection of the General Contractor includes consideration of qualifications, and they
will be part of the project team that defines the phasing of work, and the traffic
management plan, during the construction of these critical roadways 
(2)   Provides the necessary capacity improvements in support of Airport operations 
(3)   Supports, and more importantly accommodates, the SAMP Near-Term Project that
relocates the southbound lanes of the Northern Airport Expressway 
Cons: 
(1)   Given the risk the Airport Utilities Master Plan may add scope to and delay this
project, the Heavy Civil GC/CM contract may require renegotiation 
(2)   The Heavy Civil GC/CM contracting methodology requires a slightly greater capital
investment 
(3)   The Heavy Civil GC/CM contracting methodology requires stronger negotiations than
traditional GC/CM contracts 
(4)   The Port has not utilized this methodology 
This is not the recommended alternative. 



Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __8b__                              Page 6 of 8 
Meeting Date: January 22, 2019 
Alternative 4  Provide capacity improvements through two design-bid-build construction
contracts 
Cost Implications: $50,000,000 (current estimate) 
Pros: 
(1)   Provides the necessary capacity improvements in support of Airport operations for the
least overall capital investment 
(2)   Provides a phased construction approach to address potential scope risks yet to be
identified by the Airport Utilities Master Plan 
(3)   Supports and more importantly accommodates, the SAMP Near-Term Project that
relocates the southbound lanes of the Northern Airport Expressway 
Cons: 
(1)   General  Contractor  selected  only  on  price  and  the  Port  does  not  gain  General
Contractor expertise when developing phasing and traffic management plans in
support of the construction effort 
This is the recommended alternative. 
FINANCIAL IMPLICATIONS 
Cost Estimate/Authorization Summary               Capital        Expense           Total 
COST ESTIMATE 
Original estimate                                $15,600,000               $0     $15,600,000 
Cost increase                                    $34,100,000        $300,000     $34,400,000 
Revised cost estimate                          $49,700,000        $300,000     $50,000,000 
Potential future scope/cost increase                     TBD             TBD             TBD 
AUTHORIZATION 
Previous authorizations                            $260,000               $0        $260,000 
Current request for authorization                $8,340,000               $0      $8,340,000 
Total authorizations, including this request       $8,600,000               $0      $8,600,000 
Remaining amount to be authorized                   TBD            TBD            TBD 
Annual Budget Status and Source of Funds 
This project (CIP #C800866) was included in the 2018  2022 capital budget and plan of finance
as a business plan prospective project with a total budget of $15,600,000. The total estimated
cost for the Widen Arrivals Roadway project, as currently defined, is $50,000,000.  These
estimated project costs do not include potential scope additions from the Airport Utilities
Master Plan. Future budget increases, airline approval through the majority-in-interest vote, 
and construction authorizations will be phased in support of the work with budget transfers 
from the Aeronautical Allowance C800753. The funding source for this project will be the
Airport Development Fund and future revenue bonds. 

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __8b__                              Page 7 of 8 
Meeting Date: January 22, 2019 

Financial Analysis and Summary 
Project cost for analysis              $50,000,000 
Business Unit (BU)                  Roadways 
Effect on business performance     NOI after depreciation will increase 
(NOI after depreciation) 
IRR/NPV (if relevant)                N/A 
CPE Impact                        $0.09 in 2024 
Future Revenues and Expenses (Total cost of ownership) 
The operational and maintenance costs for the Airport roadway system are anticipated to
change as a result of this project.  The installation of a LED based roadway illumination system
is anticipated to reduce costs, but the installation of ITS systems, additional signage, and
landscaping areas are anticipated to increase costs. 
ADDITIONAL BACKGROUND 
In 2007 the Final Seattle-Tacoma International Airport Comprehensive Development Plan (CDP) 
NEPA Environmental Assessment (EA) and SEPA environmental review was completed. The 
CDP programmatically included the relocation of the southbound lanes of the Northern Airport
Expressway to accommodate future airfield and terminal facilities, meaning it would need
future project-level environmental review.  Thus, the project is part of the SAMP Near-Term
Projects environmental review and supports existing demand and future airport development. 
On July 11, 2017, the Commission authorized the execution of a professional services contract 
in support of the Air Cargo Road Safety Improvements project. This led to the procurement and
execution of the Airport Roadways Design Support Service contract with the HNTB Corporation
that would support both the Air Cargo Road Safety Improvements project, and the future
Widen Arrivals Roadway project if authorized by the Commission. The original contract value
was estimated at $3,000,000 to support both projects. During the planning process the scope
and estimated cost for the Widen Arrivals Roadway project increased from $15.6 million to $50 
million.  The major changes are attributed to 1) the need to accommodate the SAMP Near-
Term Projects by raising the roadway grades and providing two additional lanes to support
curbside, parking, and ground transportation operations at the Main Terminal, 2) the ne ed to
provide a third access ramp into the Main Garage to support parking and ground transportation
operations, and 3) the need for temporary roadways (detours) and the associated retaining wall
and infrastructure system relocations in order to maintain operations during construction.
Given these changes the contract value needs to be amended and increased by $2,600,000 to
$5,600,000 to provide design support services for the Widen Arrivals Roadway project. 
On September 25, 2018,  the Commission was briefed on GTAP. Several strategies were
identified to be further explored that would increase access for high occupancy modes, and
advance transportation modes and programs to foster social equity and customer choice. The

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __8b__                              Page 8 of 8 
Meeting Date: January 22, 2019 
Widen Arrivals Roadway project supports these efforts since it will provide the basic roadway
capacity and access necessary for private vehicles, commercial ground transportation, and
public transit services to access the Main Terminal and Garage. 
ATTACHMENTS TO THIS REQUEST 
(1)   Project PowerPoint Presentation 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
September 25, 2018  The Commission was last briefed on Ground Transportation to the
Airport including GTAP 
May 8, 2018  The Commission was last briefed on the status of SAMP and the start of the
environmental review process 
April 24, 2018   The Commission authorized the completion of infrastructure master
planning for Airport utility systems 
July 11, 2017  The Commission authorized design, the execution of a professional services
contract, and early pavement repair work for the Air Cargo Road Safety Improvements
project 











Template revised September 22, 2016; format updates October 19, 2016.