Poll: 520 Portage Bay bridge designs

Didn’t make it to WSDOT’s Portage Bay Bridge Community Design Meeting? No worries, here is a chance to respond to the three bridge types being considered for 520 across Portage Bay. We will have to live with this thing for the next 75 years so have a look at the design drawings in the previous post below, hold your nose if you have to, and vote below…

*UPDATE* Pros and Cons of each bridge type:

Box girder

- Hollow section bridge deck
- No additional structure above roadway – preserves views
- Spans up to 400 feet
- Heaviest footprint of columns

Extradosed

- Combination of box girder and cable stay
- Short support towers above the road surface
- Requires thicker cables – obscuring through views
- Spans up to 900 feet
- Light footprint of columns

Cable stay


- Low profile bridge deck
- Tall towers with cables, visually striking
- Thinner cables – through views somewhat preserved
- Spans up to 1200 feet
- Lightest footprint of columns

 

All images from WSDOT’s Flickr collection.

3 thoughts on “Poll: 520 Portage Bay bridge designs

  1. Really Box Girder? I don’t get it? Looks at how many pilons that thing has in the water. The Cable options are much less disruptive to the water.

  2. The cable options will become scenic landmarks. Either way you’ve got a bridge in your view, but I’d much rather be looking at the something akin to the Golden Gate Bridge, than a concrete overpass.

  3. Pingback: Issues and ideas from WSDOT’s Roanoke Lid Community Design Meeting | montlaker

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