I live in the Portland Metro area and work in Vacouver, WA. Most days, I drive to work by taking I-205 across the Columbia River (sometimes I’ll take I-5). The traffic is usually lighter and there is a fantastic view from the Glenn Jackson bridge (the I-205 bridge) as I drive over.
One thing that’s always puzzled me though, is why the bridge was built the way it was. I don’t mean the supports or columns, or artistic design, but rather the way it snakes from the Oregon shore to the Washington shore. It seems like they could have done something straighter, or… I don’t know.
So does anyone know if there was a practical reason that they would build the bridge like that?
Here is a googlemaps view of the bridge so you can see what I’m talking about. The Glenn Jackson Brdge!
To me it looks like they chose a route that had the least impact on the surrounding urbanisation (on land) and it was simply not a problem to snake the road on the water.
The first thing which comes to mind is that the alignment (route) of the bridge must be so that it connects the two sides of I-205. In all likelihood several alignments were considered and the ultimate one chosen for whatever reasons. That tells us why the abutments are where the are.
The curvature is going to be a safety thing. People traveling at highway speeds are not going to do well with sharp corners. Therefore we get our box of highway curves out and draw something folks can navigate.
I suspect that the alignment takes advantage of Government Island being a spot for construction over dry ground (economics). Note that the I-5 crossing of the Columbia also makes use of an island.
Speaking of PDX, there is a pedestrian bridge over Highway 26 in Beaverton that has the arch on the bottom rather than the top. It looks really funny, as though it were installed upside down.
It sounds like it could be any number of things (or a combination thereof) that caused them to design it this way.
From the island (Government Island) being utilized for dry ground to the alignment of the freeway on either side of the river.
I did a little more googling and came up with this.
So I think that the design and location of the highway was changed after the initial planning, which could have had an impact on the bridge design and location as well.
No, seriously, PDX. The FAA was seriously worried about jets hitting the bridge which resulted in a lot of futzing around so that it was low enough, far enough away, etc., but still high enough to let shipping under it. Note that the OR side is further away from PDX than the WA side. (The main flight paths are E-W.)
Jeez, just scroll the map in the OP to the west a tiny bit. If you drop down a line for the WA end of the bridge, you will note that it is awfully close to the end of the northernmost runway.
(Factoid of no note: I have an uncle that was a crew boss pouring concrete on the bridge.)
Well that explains something I long wondered about. The house I grew up in (the one with the brown roof immediately down and to the right of the green arrow) was purchased by my dad in 1972 shortly after it was moved out of the path of the proposed I-205 route on the Washington side. And then the highway didn’t get built, and didn’t get built, and didn’t get built … and then they finally got to work on it several years later. It sounds like they were just waiting for the Oregon side to get things sorted out.
You can’t tell from that Google photo, but 205 is down in a deep gouge they cut out right through there. For the first few years I lived in that house, the little woodsy area on the north side of the cul-de-sac filled up with rainwater every autumn, creating a small swamp/pond that was a lot of fun to explore. Then when they finally dug out the big trench for the highway, the water table dropped and that pond never filled up again (Though on the plus side, there were fewer mosquitos in the neighborhood after that.)
Also, that large, sperm whale-shaped clearing in the southwest corner of the image was a popular 'shroom gathering spot for local teenagers, or so I heard.
Not a bridge, but a different case of avoiding a runway. Or rather, moving the road when extending the runway: here. Going round the 180 degree bend at the end at night is very disorienting, as the land is completely flat all around you, and distant lights are the only illumination. And for some reason, singing the Dambusters theme while doing so makes it very entertaining. (Well, beer might’ve been the reason )
Yeah, someone who did the wiki article found a nice shot. A dusk/night shot like that shows the bizarre bridge curvature best viewed from the SR end while obscuring the unsightly industrial corridor at the Richmond end (the SR end is right next to San Quentin prison).
Great understatment. Oregonians – or would Portlanders be more accurate? – really don’t like to pay for things upfront. They would rather dither and obfuscate for a number of years before being dragging kicking and screaming into reality, only to find the final costs are many, many times more than if they just grew up and made sensible and timely decisions.
Sorry, I thought your first post was just referring to the bridge being in Portland, not the airport being the cause.
It’s funny, because the new design of the I-5 bridge is going to b very similar to the I-205 for almost that reason. The Pearson airfield is an historic location and the bridge cannot be built over a certain height because of that.
They’re replacing the current I-5 bridge? Cool. I remember the current bridge being the ugliest bridge I’ve ever seen — I haven’t seen it in person in almost 25 years, but I’ve not seen one uglier since.
(Though on the plus side, there were fewer mosquitos in the neighborhood after that.)
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