Resource Glossary
EAST LINK Light Rail
Illustrative Glossary Terms
At-grade couplet
Route located on two parallel roadways in which one
direction runs on one road and one direction on the
other road. Both routes are at street level.
At-grade/Surface
Route located at street level.
Bored Tunnel
Excavation of a tunnel or underground passage by way
of a large drilling machine. When a tunnel is bored,
surface disturbance is typically limited to stations and
portals.
Commuter rail
Also known as “Sounder “in the Central Puget Sound
region. A form of daily long distance travel by rail
mostly during peak commuting hours. Tracks are usually
shared with freight or long-distance passenger trains
(Amtrak) and are run by either electric or diesel power
(diesel in our region). Typically there is one station in
each town or city.
Elevated/Aerial Structure
Structure that is raised above the ground; a bridge.
Column/Pier
A column or pier provides structural support
to an elevated structure. (Tukwila elevated
track)
Grade-separated
Separation of transportation facilities, such as streets and rail lines,
in order to eliminate potential conflicts for right-of-way travel.
Guideway
Trackway of an exclusive rail facility dedicated to the conveyance
of train vehicles.
Mezzanine
An intermediate floor between main floors of a building. In an
elevated train station, the mezzanine would allow for the connection
of two loading platforms without the need for crossing railroad
tracks and could include ticket dispensing machines, information
kiosks and rest areas.
Operations and Maintenance (O&M) Facility
Facility designed for the storage and maintenance of transit vehicles.
An O & M facility for light rail operations for East Link may be 10 to
20 acres in size and include tracks for outside storage and a building
for maintenance and cleaning of vehicles, as well as tracks leading to
and from the facility to the main line.
Overhead catenary system (OCS)
System of overhead contact wires that supplies electrical power to
a light rail car.
Platform
Can be located on either side of rail tracks or between them. Customers
use platforms to enter or disembark trains. Platforms may have ticket
vending machines, maps and schedules available.
N
RE
BO
S
E
A
T
NE 6TH ST
T
L
NE 8TH ST
100TH AVE NE
NE 12TH ST
ST
A
EM
23RD AVE
ON
DIS
92ND AVE NE
To University
of Washington
B E L L E V U E
Lake
Washington
E
E
AV
MAIN
ST
108TH AVE SE
E CHERRY ST
BELLEVUE WAY
International District/
Chinatown Station
E YESLER WAY
A1
76TH AVE SE
BURBANK
AY
W
E
R
C
E
R
I
S
L
A
N
D
Y
D
CR
To Sea-Tac
Airport
T
ES
AVE S
AN
ISL
S
AY
M L KING JR W
BEACON
M
W
A
ER
C
ER
M
SE 36TH ST
SE 40TH ST
ME
RC
ER
W
BLVD
ON
GT
ASHIN
KE W
S
A
78TH AVE SE
LA
E
AV
S SPOKANE ST
Se
gm
gm en
en t B
t
Se
PARK
R
INIE
RA
AIRPORT WAY S
4TH AVE S
1ST AVE S
72ND AVE SE
LUTHER
Mercer Island
Park & Ride
E
A
SE
Segment
23RD AVE S
S JACKSON ST
WY
341526.P1.09.01.EN_TB072006007SEA_Scoping_Report/Maps/Routes_For_EIS/Segment_A_Alt_DEIS_012507 . gr
Central Link Alignment and Station
Adjacent Segment
N
Segment A
I-90: from the International District/Chinatown Station in Seattle
across Mercer Island to the east side of Lake Washington.
A B Segment Limit
City Limits
Retained cuT
A trench; the retention of an excavated area or land by way of a
reinforced or stabilized wall in order to create space for a road,
structure or train tracks.
At-Grade
0
B2-E
O
gh East
st
r Sl
ou
hW
e
rce
ug
Me
NE 8TH ST
B E L L E V U E
C7-E
C4-A
Seg m e n
tD
Seg m e n
tC
116TH AVE NE
C3-T
112TH AVE NE
PARK
C3-T
C4-A
C7-E
C8-E
East Link Project
C8-E
12
TH
ST
Bellevue
NE 8TH ST
BNSF RR
Bellevue
Transit Center
NE 6TH ST
NE
Lake
110TH AVE NE
NATURE
NE 10TH ST
108TH AVE NE
SLOUGH
1 Mile
RD
123RD AVE SE
MERCER
0.5
NE 12TH ST
B7
118TH AVE SE
rS
lo
R
0.25
C8-E
106TH AVE NE
108TH AVE SE
SE
AY
E W
104TH AVE SE
Merce
T
EC
NN
CO
ST
SE 8TH
E
S
LL
K el s e y Cr ee k
B2-E
B2-A
B3
L AK
HI
112TH AVE SE
EVU
BELL
B E L L E V U E
B3
B3
B7
Wilburton
Park &
Ride
RR
B2-A
B1
BELLEVUE WAY NE
SE 6TH ST
SF
C
B
BN
Segment
Segment
Exhibit: Segment A Alternative
to be Evaluated in the DEIS
Route Profile
Proposed Station
C1-T
C2-T
LLE
BE
C7-E
E
VU
NE 4TH ST
Y
WA
NE
SE
0
0.125
ugh E
ast
rS
lo
rce
Me
0.25 Mile
Exhibit: Segment B Alternatives
to be Evaluated in the DEIS
East Link Project
RR
§
SE 6TH ST
C2-T
C3-T
C4-A
C7-E
C8-E
F
Elevated
C
B
C2-T
C3-T
C4-A
C7-E
C8-E
S
BN
Proposed Station
116TH AVE NE
A
City Limits
C2-T
C3-T
C4-A
C7-E
C8-E
B
t
en
n
Segment
Segment B
South Bellevue: from the east side of Lake
Washington through South Bellevue to SE 6th Street
in Bellevue.
At-Grade
reek
ant C
SE
t
m
hi
en
m
as
Route Profile
Sturtev
E
AV
g
Se
g
Se
W
Segment
Adjacent Segment
ST
108TH AVE NE
BELLEVUE WAY NE
H
B7
Source: King County (2006) modified by CH2M HILL
4TH
MAIN ST
ST
MERCER SLOUGH
NATURE PARK
112TH AVE NE
C7-E
C8-E
B7
PARK
341526.P1.09.01.EN_TB072006007SEA_Scoping_Report/Maps/Routes_For_EIS/Segment_B_Alts_DEIS_031907 . gr
A B Segment Limit
C8-E
114TH AVE NE
NATURE
B2-E
B1
B2-A
B2-E
B3
B7
SE 34TH
C4-A
SLOUGH
113TH AVE SE
6T
10
ke
on
C3-T
NE 2ND ST
R
F R
ARTS
La
gt
MERCER
South Bellevue
Park & Ride
108TH AVE SE
BEAUX
BNS
B1
B2-A
B3
SE 25TH ST
C2-T
C1-T
Segment
Segment
341526.P1.09.01.EN_TB072006007SEA_Scoping_Report/Maps/Routes_For_EIS/Segment_C_Alts_DEIS_032007 . gr
Adjacent Segment
Route Profile
Tunnel
§
C
B
Source: King Country (2006)
Segment C
Downtown Bellevue: from SE 6th Street through
downtown Bellevue to the east side of I-405.
B C Segment Limit
City Limits
Proposed Station
Retained Cut
At-Grade
Elevated
0
0.125
0.25 Mile
Exhibit: Segment C Alternatives
to be Evaluated in the DEIS
East Link Project
Va
D2-A
D2-E
D3
D5
lle
y Creek
Sa
E1
ma
134TH AVE NE
sh R
iver
NE
RD
NE 80TH ST
r
Bea
Creek
E2
E4
mi
R E D M O N D
E
F R
R
AV
ON
DAL
R E D M O N D
A
LE
RY
Y
WA
NE
NE
520
RE
DM
ON
D
6 TH S T
NE 7
WA
Y
E1
E4
D3
OLD REDMO
ND
BEAR CREEK PKWY
Bear Creek
R
SF
D
BN
Gof
RR
NE
PL
H
re e
k
yC
k
el
se
ree
PARK
r
NE
Route Profile
§
Source: King County (2006)
T ST
NE 51S
Segment D
Bel-Red Corridor: from NE 12th Street and 116th Avenue NE to the
Overlake Transit Center.
Retained Cut
At-Grade
Elevated
0
0.25
0.5 Mile
Exhibit: Segment D Alternatives
to be Evaluated in the DEIS
East Link Project
520
Segment
Lake Sammamish
E
D
172ND AVE NE
Segment
156TH AVE NE
Proposed Station
MARYMOOR
Riv
e
AY
W
RK
PA
C
ey
Adjacent Segment
am
ish
H
IS
AM
M
M
K
K
mm
SA
B E L L E V U E
RD
341526.P1.09.01.EN_TB072006007SEA_Scoping_Report/Maps/Routes_For_EIS/Segment_D_Alts_DEIS_012507 . gr
C D Segment Limit
Sa
KE
LA
136T
D3
T
E-R
E1
E2
E4
e ls
124TH AVE NE
NE
EVU
BELL
OND
EDM
E1
E4
E2
ES
W
ek
D2-A
D2-E
D3
156TH AVE NE
e
y Cr
ST
Sears Creek
NE 20TH ST
140TH AVE NE
se
D2-A
D2-E
D3
130TH AVE NE
el
TH
WA
Y
132ND AVE NE
fK
12
P
151ST AVE NE
st T
Segment C
Segment D
D2-A
D2-E
D3
D5
NE
o
D3
152ND AVE NE
We
RT
HU
ry
148TH AVE NE
NO
uta
"
D3
Overlake
Park & Ride
152ND AVE NE
f Creek
120TH AVE NE
116TH AVE NE
NE 16TH ST
D2-A
D2-E
D5
NE 24TH ST
D5
520
D5
r ib
City Limits
"
)
BNS
NE
AVE
Overlake
Transit
Center
B E L L E V U E
NE 83RD ST
Redmond
Park & Ride
154TH
Segment D
166TH AVE NE
Segment E
164TH AVE NE
NE 40TH ST
NE 40TH ST
Overlake
Transit Center
Source: King County (2006)
341526.P1.09.01.EN_TB072006007SEA_Scoping_Report/Maps/Routes_For_EIS/Segment_E_Alts_DEIS_012507 . gr
Adjacent Segment
Route Profile
§
Segment E
Redmond: from north of the Overlake Transit Center
to downtown Redmond.
D E Segment Limit
City Limits
Proposed Station
Staging Area
A temporary site used for the storing and staging of construction
equipment and material. (Beacon Hill Station)
Retained Cut
At-Grade
Elevated
0
Subway
An underground railway.
0.125
0.25 Mile
Exhibit: Segment E Alternatives
to be Evaluated in the DEIS
East Link Project
Tunnel Portal
Exiting or entry way of a tunnel.
Textual Glossary Terms
Alignment
Route or path of the train.
Boardings
Number of individuals boarding or getting on a train. If you took one train to and from
a destination, you would make two (2) boardings during your round-trip.
Catenary
Overhead contact wire that supplies electrical power to a light rail car.
Conceptual engineering
Initial design steps in a project. Generally taken to represent a 5-10% level of design.
Corridor
Generalized travel or transportation path. The area on either side of a transportation
facility.
Cut-and-cover construction
Method for constructing tunnels, underground stations or other underground facilities
close to the surface by excavating from above and then covering the opening with a
permanent lid.
Density
Number of units in a given area. For example, 100 residential units per acre may be
considered a very densely developed acre of land.
Environmental Impact Statement (EIS)
Public document that discloses and evaluates the potential environmental impacts of a
proposed project. The EIS may be subject to State or Federal requirements.
Final design
Preceding actual construction, this final step of engineering design moves the project
to the 100% design, ready for construction.
GMA
Growth Management Act. Adopted by the State of Washington to manage projected
growth in a coordinated and planned fashion and direct growth to designated areas
based on an area’s ability to support said growth.
Grade
Grade or steepness of a natural or man-made incline or hill.
HCT
High Capacity Transit. A form of public mass transit systems capable of moving large
numbers of passengers along a dedicated right-of-way.
Light Rail
Light rail is an electric railway powered by an overhead power source. Light rail is versatile
and flexible enough to run at street level, through tunnels, or in elevated right-of-way,
depending on individual routes.
level boarding
Station boarding from a platform that is at the same level as the low floor of the train car
or bus. Used so those in wheelchairs and strollers are easily and quickly accommodated
(no steps needed) and to speed loading.
Low-level platforms
Station platforms that are typically 14 inches high.
Mitigation
Specific actions required and taken to reduce the scale, size or extent of an identified
impact resulting from the implementation of a major construction project.
One seat ride
Trip that can be completed without transferring vehicles.
Preliminary engineering
Advances a design to the 30% design level and further develops the details for the
project before final design commences.
Profile/vertical alignment
Determines whether an alignment is a tunnel, elevated structure or on surface level.
R8A
The preferred alternative adapted by I-90 Two-Way Transit and HOV project. This
alternative provides HOV lanes in two existing outer roadways of the I-90 floating
bridge creating two-way, all-day HOV lanes for transit and carpools.
Regional Transportation Investment District/RTID
Entity created by the Washington State Legislature and charged with developing a
transportation package to be submitted to voters in the fall of 2007 for improving significant
highways and bridges in Snohomish, King or Pierce Counties. RTID is coordinating its
work with Sound Transit, which will submit a companion transit proposal to voters.
Ridership
Number of passengers who ride public transport systems.
Right-of-way
Easement or strip of land dedicated to public transportation uses and facilities.
Roads & Transit Partnership
Joint effort by Sound Transit and the Regional Transportation Investment District (RTID)
to create the first-ever integrated set of highway, bridge and transit improvements for
Snohomish, King and Pierce counties.
Route
Systematically assigned line or course of travel for a specific area or territory.
Sound Transit Board of Directors
18-member appointed governing body of the Central Puget Sound Regional Transit
Authority (Sound Transit). The Board establishes policy, provides direction, and performs
oversight. Sound Transit is governed by an 18-member Board of Directors; 17 members
are local elected officials, and the 18th member is the Washington State Department of
Transportation Secretary. Local elected officials include mayors, city council members,
county executives, and county council members from within the Sound Transit District.
Currently, the Sound Transit Board includes three members from Snohomish County, ten
from King County, four from Pierce County, and the State Transportation Department
secretary. The Board of Directors are:
John W. Ladenburg, Executive, Pierce County
Connie Marshall, Councilmember, City of Bellevue,
Mark G. Olson VP, City of Everett Council
Julie Anderson, Councilmember, City of Tacoma,
Mary-Alyce Burleigh, Councilmember, City of Kirkland
Fred Butler, Deputy Council President, City of Issaquah
Dow Constantine, Councilmember, King County Council
David Enslow, Mayor, City of Sumner
Doug MacDonald, Secretary, WSDOT
Richard L. Marin, Councilmember, City of Edmonds
Richard J. McIver, Councilmember, City of Seattle
Greg Nickels, Mayor, City of Seattle
Julia Patterson, Council Vice Chair, King County Council
Larry Phillips, Councilmember, King County Council
Aaron Reardon, County Executive, Snohomish County
Ron Sims, County Executive, King County
Claudia Thomas, Mayor, City of Lakewood
Peter von Reichbauer, Councilmember, King County Council
Straddle Bent
On an elevated structure, straddle bent is a bridge structure that
straddles both sides of the street. Used when elevated light rail
makes a turn.
ST2
Sound Transit 2. The second phase of regional transit investments for
the Central Puget Sound.
Traffic signal pre-emption
Ability to over-ride traffic signals in order to give priority to approaching
vehicles, such as emergency vehicles. Also used in light rail systems
operating at surface level.
Traffic signal priority
Allows specially equipped buses or trains to communicate with an
approaching traffic signal and ask it to hold the green light for a bus
or train. A transponder installed on the bus or train sends a signal to a
controller on the traffic light.
Transition structure
Structure or ramp designed to transition trains from an at-grade facility
to an elevated facility.
Trips (are one way)
Recorded one-way travel via public or private vehicle from the origin
of the trip to a destination.
Urban Design
Concerns the arrangement, appearance and functionality of towns,
cities and urban open spaces.
WSDOT
Washington State Department of Transportation.