City of Seattle

Portage Bay BridgeVision

September 2014

Design vision for Portage Bay Bridge:

� The Portage Bay Bridge is both a distinctive and context-sensitive element within the family of SR 520 bridges.

� The bridge serves as a connecting thread, tying together the tree-covered Roanoke ridge to the west and the heart of the residential, research and multimodal transportation at Montlake to the east.

� With the recommendation of a shared-use path, the Portage Bay Bridge helps to complete regional connectivity for all modes of users throughout the SR 520 corridor.

Cable stay concept

Box girder concept

DRAFT

Cable stay concept

View from the Seattle Yacht Club looking southeast

FOR DISCUSSION PURPOSES ONLY

City of Seattle

Existing bridge

Cable stay concept

Box girder concept

Portage Bay BridgeView from University bridge looking southeast

September 2014

FOR DISCUSSION PURPOSES ONLYDRAFT

City of Seattle

September 2014

Box girder

Cable stay concept

Box girder concept

Both concepts meet our vision and goals by:� Gap between structures allows: � More light to reach the water and land below � Provides break in bridge width� Raised bridge profile on east end provides boaters with easier access and improved views

Portage Bay BridgeView from under bridge looking west

DRAFT FOR DISCUSSION PURPOSES ONLY

City of Seattle

September 2014

Cable stay concept

Box girder concept

Portage Bay BridgeView from 10th and Delmar lid

Both concepts meet our vision and goals by:� Minor and major elements provide function, lighting, signage support and provide a sense of rhythm moving across bridge� Cable elements create a unique moment on the bridge, which changes at different perspectives

DRAFTFOR DISCUSSION PURPOSES ONLY

City of Seattle

Cable stay concept

Box girder concept

Both concepts meet our vision and goals by:� Shared-use path provides local and regional connectivity for all users� Raised bridge profile on east end improves access for all users� Path provides views � Bridge elements help provide scale to the user experience and add visual interest

Portage Bay BridgeView of shared-use path looking west

September 2014

DRAFT FOR DISCUSSION PURPOSES ONLY

City of Seattle

September 2014

Cable stay concept

Box girder concept

June 17, 2014 concept

July 8, 2014 concept

June 17, 2014 concept

SCDP concept, 2012

Portage Bay BridgeElevation and profile design studies

July 8, 2014 concept

SCDP concept, 2012

DRAFTFOR DISCUSSION PURPOSES ONLY

14’Managed shoulder

11’GP

11’GP

11’GP

11’GP

8’Shoulder

12’Transit/HOV

12’Transit/HOV

2’ 6’ 2’plantedmedian

Sho

ulde

r

Sho

ulde

r

105’

1.5’ 1’1’ 1.5’

133’

14’Managed shoulder

11’GP

11’GP

11’GP

11’GP

8’Shoulder

12’Transit/HOV

12’Transit/HOV

2’ 19’ 2’gap between

structures

Sho

ulde

r

Sho

ulde

r

1.5’ 1.5’1.5’14’

Shared-use path

1.5’

BOYER AVE E

10th AND DELMAR LID

TF 007TF 053TF 012TF 241

-2.6%

TF 061TF 061TF 102TF 052TF 052TF 00310

2 FT

149

FT129

FT

190

FT

147

FT

224

FT

QCYC

MONTLAKE LID

10th AND DELMAR LID

MONTLAKE LID

BOYER AVE E

-4.6%

QCYC-1.9%

300 FT225 FT 150 FT typicalTF 002TF 003142 FT

Portage Bay Bridge Options Comparisons

Elevation views looking north

Section views looking east

NOTE: The shared-use path is not included in the baseline design.

September 2014

FEIS baseline

Box girder north shift

Cable-stayed north shift

FEIS baseline

Split box girder and cable stay north shift

faux arches

W E

W E

W E

10th AND DELMAR LID

MONTLAKE LID

BOYER AVE E

TF 053TF 012TF 241

-2.6%

TF 061TF 061TF 102TF 052TF 052TF 003

QCYC

350 FT 350 FT

DRAFT