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Attornatus_Oregonensis
08-01-2007, 07:29 PM
As you probably know, Multnomah County is currently studying options for a new Sellwood Bridge. Some people in my neighborhood, Sellwood, and here on bikeportland have suggested that the most sustainable solution would be to decommission the bridge for motor vehicle traffic and make it a ped-bike bridge. The County is not currently considering this option.

But after living in the neighborhood for a few months and doing a little preliminary research (I'm a recent transplant from Seattle), I realized that (a) many (or most) people who use the bridge are from Clackamas County, or elsewhere outside the neighborhood, on their way to and from the west side of the Willamette (and those from Clackamas who use the bridge will not pay for its replacement); (b) these people regularly clog and speed through Sellwood's main street, making it difficult for its residents to get around, creating a dangerous situation, and generally lowering the livability of the neighborhood; and (c) the Sellwood Bridge roadway is essentially impassible by bicycles due to impatient, aggressive motorists and cyclists are forced to go across a narrow, almost unrideably narrow sidewalk.

From this, I have concluded that the Sellwood Bridge and its current replacement plans represent a continuation of America's unhealthy, unsustainable, and self-destructive car-centric public policy. It perpetuates and finances so many of the key problems facing our society: peak oil, global climate change, unsustainable development, hazardous air pollutants, and the obesity epidemic. It is both a bad solution to local transportation problems and a commitment of pubic funds that exacerbates key problems facing one of the county's nicest neighborhoods. Thus, I want to draft a petition that calls for decommissioning the Sellwood Bridge. I want to send a message that the residents of the Portland area value people over cars.

Because of other commitments, I currently have little time to do research on the County's findings related to the Bridge and the replacement project. Is anyone willing to help me do some basic research on facts related to these issues? Write the petition? Canvass some nearby neighborhoods for signatures? If so, please write me at cmheaps@gmail.com. Thanks.

Rixtir
08-01-2007, 08:11 PM
Decommissioning the bridge would certainly solve the problem they currently face of trying to fit a new bridge into the existing area.

Somebody here once suggested making one of the bridges a market bridge (perhaps like the pontevecchio?). Don't remember if it was the Sellwood or not. Seems a bit far removed from central Portland for that, and would probably interfere with cyclists and runners, but shows what we can come up with for this town with a little creativity.

wsbob
08-01-2007, 08:34 PM
AO, you're not simply suggesting to decommission the Sellwood for motor vehicles and not build a replacement motor vehicle bridge into the Sellwood area are you? I really doubt transportation officials would go for that, unless a replacement bridge to handle the traffic was located somewhere else.

I'd like to hear an engineers opinion about the feasibility of allowing the Sellwood to function as an exclusively pedestrian/non-motorized bridge; what the estimated structural integrity might be for that particular use on a present and long term basis, and also, the estimated yearly and long term maintenance expenses. If such an opinion is favorable, then decommissioning for exclusive bike/pedestrian use might be a good idea.

Rixtir
08-01-2007, 08:39 PM
I'd like to hear an engineers opinion about the feasibility of allowing the Sellwood to function as an exclusively pedestrian/non-motorized bridge; what the estimated structural integrity might be for that particular use on a present and long term basis, and also, the estimated yearly and long term maintenance expenses. If such an opinion is favorable, then decommissioning for exclusive bike/pedestrian use might be a good idea.Given that a major bridge just collapsed into the Mississippi, I'd be leery of any decommissioned bridge that didn't meet the appropriate structural integrity standards for the proposed use.

SpeedRacer
08-01-2007, 08:49 PM
The second I learned of that miss. bridge collapse, I knew the trolls would come out re: sellwood and be spouting off this and that...

"call me miss cleo" on this

Rixtir
08-01-2007, 08:53 PM
The second I learned of that miss. bridge collapse, I knew the trolls would come out re: sellwood and be spouting off this and that...

"call me miss cleo" on thisNot trolling at all. In an imaginary scenario where the bridge is decommissioned and put to cycling/pedestrian use only, that doesn't excuse the county from certifying that the bridge is safe for that use, and making whatever repairs are necessary to keep it safe. What part of that is hard to grasp?

Attornatus_Oregonensis
08-01-2007, 09:20 PM
AO, you're not simply suggesting to decommission the Sellwood for motor vehicles and not build a replacement motor vehicle bridge into the Sellwood area are you? I really doubt transportation officials would go for that, unless a replacement bridge to handle the traffic was located somewhere else.

Yes, that's exactly what I'm proposing. I really don't think the opinions of transportation officials should be treated with too much gravity here. They've consistently favored expending billions and billions of public monies to subsidize private single-occupancy vehicles in projects such as this without any considerations for the wider negative impacts. It's time for new and different thinking on transportation. The current policies are not sustainable and will lead to nothing short of social ruin in the long-run. And if the continued pursuit of the single-occupancy vehicle commute really becomes untenable for the Clackamites without the Sellwood Bridge, let them use their own tax money to build a bridge across the river. The rest of us can use the Ross Island when we *need* to drive.

As far as the structural integrity for bikes and peds goes, that's a problem that can easily be solved for a fraction of the cost of a new bridge. Any discussion of that now is an attempt to distract from the broader issues here.

Rixtir
08-01-2007, 09:48 PM
As far as the structural integrity for bikes and peds goes, that's a problem that can easily be solved for a fraction of the cost of a new bridge. Any discussion of that now is an attempt to distract from the broader issues here.No, I'm not trying to distract from the discussion of the decommission. Just commenting on a point that wsbob raised about structural integrity. Of course it would be much cheaper, because it wouldn't have to be strengthened to support the vehicle weights and trips that it currently supports. If anything, that cheaper cost-- if any strengthening is even needed for a pedestrian/cycling bridge-- is a selling point, rather than a distraction.

cecilanne
08-01-2007, 10:00 PM
But after living in the neighborhood for a few months and doing a little preliminary research (I'm a recent transplant from Seattle), I realized that * * * (b) these people regularly clog and speed through Sellwood's main street, making it difficult for its residents to get around, creating a dangerous situation, and generally lowering the livability of the neighborhood;

You thinks it's bad now - you should have seen it a few years ago before they changed the traffic flow patterns on Tacoma . . .and you should have heard the bitching from the motorists about THAT change. Although I like the idea of decommissioning the bridge, I can guarantee a firestorm of opposition to the concept of taking out the only river crosing between Oregon City and downtown . . .

wyeast
08-01-2007, 11:32 PM
I can't state for certainty, as I'm not professionally involved w/ the Sellwood Bridge project. However, my understanding is that at least a fair portion of the structural work needed to the bridge (seismic retrofit, stabilization of the westside approach due to sliding hillside) has very little to do with vehicle vs. bicycle weights. So I wouldn't necessarily assume that it would be "cheap" to fix the Sellwood as a MUP-only bridge.

Would it be cheaper than building an all-new bike/pedestrian bridge? Probably. Would it be cheaper than the expense of adding width to whatever replacement vehicle bridge to provide for proper bike/pedestrian flow? That's a stickier point to determine, especially since it's already obvious that the bridge needs to be replaced as far as vehicle traffic is concerned.

wsbob
08-02-2007, 12:28 AM
I never yet seem to have the energy to do the research that I'd like to provide, but concerning the structural integrity of the Sellwood, I'm certain that quite a lot about its present status is already known. Learning about what that is, is a matter of tracking down articles that have been written in the O (I've read some of them) as well as elsewhere probably, accessing and reading reports, and maybe even talking to engineeer employees involved in repair and maintenance.

As I recall, the bridge has had some patches installed; big steel plates bolted to the understructure or some such thing, to a certain extent, to help the bridge withstand the weight and vibration of today's high traffic volume. The thing is, I think the article I read said there's cracks and so forth under those patches too. Years of heavy use could have damaged it as well as putting under a lot of stress.

And then there's the possibility of age and material failure that may factor into whether the Sellwood has a viable future as an exclusive ped/hpv bridge. On the Sauvie Island Br thread, I was trying to remember the beautiful coastal bridge that had to be replaced because of age and why. The Alsea Bay Bridge, I believe. I think it's problem was steel re bar embedded in concrete that had rusted and cracked the concrete. No idea whether that's a factor in the Sellwood.

The bridge has to be able to support itself, even if heavy, heavy vehicles aren't pounding on it for many hours a day.

I'd be glad for the Sellwood neighborhood if it could get a motor vehicle crossing located elsewhere. I don't see that the planners and the power structure are thinking big enough to devise some arrangement that allow that to happen, but I'm sure interested in hearing about it if they or anyone else is.

mtmann
08-02-2007, 12:07 PM
While I appreciate the sentiment and would LOVE to see a bike/pedestrian only crossing of the Willamette, surely I can't be the only one who cringes at the thought of riding across a crumbly old bridge that has been deemed unsafe for cars and trucks? That sucker's waaay above the water!

SpeedRacer
08-02-2007, 09:18 PM
What part of that is hard to grasp?

Your timing is off. Let the bodies get cold at least, thanks.

Rixtir
08-03-2007, 03:46 PM
Your timing is off. Let the bodies get cold at least, thanks.No need to thank me, because A) I have no intention of complying with your request, and B) you clearly don't know what a troll is.

Attornatus_Oregonensis
03-19-2008, 08:39 AM
From this morning's Oregonian:

http://www.oregonlive.com/news/oregonian/index.ssf?/base/news/1205895314293830.xml&coll=7&thispage=1

wsbob
03-19-2008, 09:38 AM
This could get very interesting. Commissioner Rojo is now thinking seriously of closing the Sellwood. The conservative guy Lonnie Roberts and Lisa Naito are leaning that direction also.

"A closure could create serious traffic problems, with an estimated 20,000 additional cars heading to the nearby Ross Island Bridge or other downtown crossings every day, said Mike Pullen, a county spokesman on bridge issues." ARTHUR GREGG SULZBERGER/The Oregonian Staff

Or, at least some of the drivers of those cars might decide to try the bus. Or, a bicycle. While the Sellwood Bridge might reasonably be closed because of concerns about it's ability to withstand the strain of motor vehicle weight and vibration, the weight and vibration of many cyclists upon it would probably represent a much reduced strain upon the bridge structure.

Attornatus_Oregonensis
03-19-2008, 09:56 AM
"[S]ome of the drivers of those cars might decide to try the bus. Or, a bicycle. While the Sellwood Bridge might reasonably be closed because of concerns about it's ability to withstand the strain of motor vehicle weight and vibration, the weight and vibration of many cyclists upon it would probably represent a much reduced strain upon the bridge structure.

Exactly. Closure would give all those folks a chance to try something other than the single-occupancy vehicle as a way to get to work. And, believe me, it's one SOV SUV after another through Sellwood each morning and evening. It will cause a bit of a strain for Ross Island, but that would likely be temporary, given that the Max train from Milwaukie to downtown will come online in just five years. And in the meantime, try a bus or a bike or a carpool.

Put more bluntly, closure would make the SOV a less attractive commuting option. And that's the only way we're ever going to reduce our greenhouse gas emissions, achieve energy independence, and solve the other transportation and liveability problems created by the SOV. That's why closure of the Sellwood Bridge is the most progressive policy option.

As for the bridge itself, it is only at structural risk because of the weight of motor vehicles. It would be fine for bikes. It could become a permanent, historic and safe link for the Springwater and the trail on the west shore of the Willamette and the cemetary route. Creating a safe river crossing for bikes here would also encourage more people to bike, yet another reason why closure is the most progressive policy option.

Duncan
03-19-2008, 09:56 AM
While the closure would directly effect my neighborhood (I live off Powell, take Powerl to the Freeway to get to work) I would much rather see that then a bunch of people killed if the Sellwood Bridge Collapsed.

Maybe a closure could be offset by some increased bus service (an express bus in the affected communities?), bike Blvd increases? I dont know I just dont want us to have a diaster such as the one that happened in Mpls.

Attornatus_Oregonensis
03-19-2008, 11:04 AM
It would be really easy for Metro to step-up, survey where all those Clackamites are going each morning in their SOV SUVs, and provide express bus service accordingly. And not having to re-build the bridge should create substantial cost savings.

Cruizer
03-19-2008, 11:33 AM
I was so grateful to the city councils of Troutdale, Maywood Park and Gresham for speaking out and refusing to force Multnomah County residents to pay for a bridge for Clackamas County commuters.

I think several factors indicate that the timing is good for considering decommissioning the Sellwood and refurbishing it (or replacing it) as a bike/ped crossing. The steadily climbing price of gas, coupled with the construction of the light rail along I-205, may work together to prompt many long-distance Clackamas commuters to consider switching to mass-transit.

With the precarious state of our economy, the money just isn't going to be there for the huge bridge replacement currently envisioned. As economic conditions worsen, I think there's a good chance that a considerable percentage of Americans are going to be willing to reconsider where they live in relation to where they work and maybe change one or the other so they have a shorter commute and can either bicycle to work or use mass transit.

One thing's for sure, as our government keeps bailing out banks and financial firms and accepting their high-risk mortgages as collateral, there's not going to be much money left over for new bridges -- across the Willamette or the Columbia.

nuovorecord
03-19-2008, 01:58 PM
It'd be interesting to see what exactly would happen with traffic if the bridge were to be closed. Typically, everyone screams bloody murder when road capacity is removed. But people find other routes, other modes, other ways of dealing with it and the impact is never as severe as predicted.

One thing to also keep in mind: Commissioner Wheeler made a pitch to JPACT about creating a regional bridge fund so all the users pay for the bridge, not just MultCo residents. A good idea on its face, but the problem was that he was requesting regional flexible funds to do it.

Why this is a problem is that those flexible funds are the only source of funds available for bicycle and other alternative mode projects. In contrast, there are millions of dollars available for road projects in the region, from a variety of sources, which are a better source of funding for what Wheeler is proposing. Something to keep your eye on. It's in the minutes, scroll to page 19 in the .pdf

http://rim.metro-region.org/webdrawer/rec/176765/view/Planning%20Department%20-%20Administration%20-%20J~tee%20on%20Transportation%20-%20Meeting%20Agendas,%20Packets,%20Minutes%20and%2 0Exhibits%20-%20Packet.PDF

Attornatus_Oregonensis
03-19-2008, 02:33 PM
Very interesting. A toll is the obvious answer - you use it, you pay for it.

Another obvious solution would be for Multnomah County to offer to sell Clackamas County some interest in the bridge in return for contributing to its re-build. Why would Clackmackistan want to do that? Because their citizens benefit from having a Sellwood Bridge and otherwise whether it gets re-built, and how, is all decided by Multnomah County.

But all of these work-arounds ignore the one fundamental fact: There is broad consensus that our policy needs to be to decrease motor vehicle trips. Re-building the bridge doesn't accomplish that goal, but de-commissioning it and making it a bike-ped crossing does.

Oldguyonabike
03-19-2008, 03:01 PM
OK - caveat- I am not a civil engineer.
But my son is and he specializes in concrete and bridges. He's also a rider.
I asked him about the pedestrian / cycle option as it seems as obvious to me as to all of you commenting on it. He tried to explain to me that weight distribution of cars going over a bridge is more evenly dissipates the load than peds. He agrees its counter intuitive and I never quite understood. But, it turns out that a loaded bridge full of people (or bikes - think Bridge Pedal) is a larger load on the bridge than bumper to bumper traffic.
Who'da thought?

Attornatus_Oregonensis
03-19-2008, 03:38 PM
Well, no offense, but I tend to be pretty skeptical of claims like that. I'd probably need a little bit more evidence before I would believe that a bridge would be more likely to collapse under the weight of someone on a bicycle than someone in a truck.

After all, the fact is that the bridge is regularly open for the Bridge Pedal and is and remains closed to large trucks, specifically because of their weight. That fact makes pretty clear to me that whatever your son is selling isn't true with respect to the Sellwood Bridge. Either that, or the current Multnomah County engineers, who have specific experience with the Sellwood Bridge, are wrong. Given those facts, as I said, I'd need a little more evidence and some way to explain why the policy is the way it is before I'd be willing to believe your report.

Oldguyonabike
03-19-2008, 04:22 PM
I'll e-mail him and post his response. It didn't make sense to me at first either, but he eventually convinced me. It had to do with being able to pack more people on to the bridge than what fits into a car. And with weight distribution, I think, too.
He's slow at responding to e-mails from Pops so patience.

nahbois
03-19-2008, 08:53 PM
maybe I'm going crazy...

but I could have sworn there was some proposal that I saw in the portland tribune where money is being raised to move the sellwood bridge to Flanders in the Pearl, and make it a pedestrian access over I-405.

wsbob
03-19-2008, 09:01 PM
(^....nahbois, you're not crazy....you're just confusing the Sellwood Bridge with the recently replaced Sauvie Island Bridge !!)

Theoretically, given specific conditions, Oldguy's son is going is probably right. A typical human's weight is loaded vertically on a square foot base of about 3 sq ft. Would completely filling the entire deck of the Sellwood Bridge with standing people exceed the gross weight of typical cars and passengers that the lanes of the bridge could hold? I'm not a math/engineer type, so I can't say, but I'll bet this isn't too hard to figure out.

At any rate, people aren't going to be standing shoulder to shoulder on a bridge closed to motor vehicle traffic and dedicated to bike/pedestrian use for commuting purposes. People using such a bridge would be spaced much farther apart. It logically follows that the weight loading represented would be far less than that of the bridge deck completely filled with standing people, and less than that of motor vehicles that use it. For sure, the vibration factor from cyclists would be less than from far heavier motor vehicles.

wlrdr
03-20-2008, 08:45 AM
I realized that (a) many (or most) people who use the bridge are from Clackamas County, or elsewhere outside the neighborhood, on their way to and from the west side of the Willamette (and those from Clackamas who use the bridge will not pay for its replacement); (b) these people regularly clog and speed through Sellwood's main street, making it difficult for its residents to get around, creating a dangerous situation, and generally lowering the livability of the neighborhood;

And Californians are invading...

This is a regional transportation issue and needs to be dealt with as such.
The decommissioning of the Sellwood without a motor vehicle replacement in that vicinity is unrealistic. It simply won't happen.

Ride safe.

Attornatus_Oregonensis
03-20-2008, 09:15 AM
About as unrealistic as building a bridge with no money, or expecting only Multnomah County residents to pay for it? Yeah, about that unrealistic.

Oldguyonabike
03-21-2008, 10:49 AM
OK - as promised here's the engineer's perspective. Remember that designers are obligated to be extremely conservative with designs because they don't like bridges they've designed to crumble:

"You can liken it to the pedestrian load at the 50th anniversary of the Golden Gate Bridge in 1987. At this event approx. 300,000 people were on the bridge simultaneously, this created such a load that the bridge’s camber was noticeably reduced (something that is difficult to do). To this date, this is the largest load that has been placed on this bridge.

This is also a problem for older bridges (like the Sellwood) that were designed using older codes. Keep in mind that bridges and roads are not (and never will be) designed for cars, they are designed for trucks. 70-100 years ago, the “design truck” was an order of magnitude smaller than the current code stipulates. Counterbalancing this is the fact that engineers used to have less knowledge about the structures they designed, so everything was built conservatively. At the end of the day however, old bridges do not meet the loading requirements of current design codes (hence the truck load limits you see on many older bridges) and would also probably be deficient for a pedestrian bridge design.

This effect is different depending on the type, width, and geometry of a bridge. Pedestrian loads are not trivial however, and pedestrian bridges have very strict design codes. I will get a more convincing (i.e. analytical) argument later, but you are justified in your skepticism of the Sellwood’s ability to be a safe and effective pedestrian facility."

sabernar
03-21-2008, 11:02 AM
I seriously doubt the Sellwood bridge, if converted to a ped/bike bridge would have anything close to the density of 300,000 people on the Golden Gate. On a normal day how many people would be on it at the same time? 20? 100? Let's say 100. That's what?, ~15,000 lb distributed across the bridge. That's the equivalent of 3 or 4 SUVs.

I'm not saying that the Sellwood Bridge is safe to use as ANY type of bridge, but for normal use, there's no way a ped/bike bridge comes close to wear and tear of a car/truck bridge.

You can always come up with a scenario that won't work. What if the Pacific Northwest Obesity Club staged a march across the bridge in lock step. How could the bridge hold up?!?! Because of that, we shouldn't convert it into a ped/bike bridge!

Tait
03-22-2008, 03:56 AM
What if the Pacific Northwest Obesity Club staged a march across the bridge in lock step. How could the bridge hold up?!?!

Those are exactly the kinds of scenarios engineers must consider, and then add in a safety factor of probably 2-3x. It doesn't matter that the bridge may never actually be jam-packed with people. If it could possibly be jam-packed with people (marchers, bridge pedal, protesters... whatever), it's going to look pretty bad if the bridge collapses and the engineer says "Well, I never thought there'd be that many people on the bridge." And a defense of "well they didn't read the posted sign" isn't going to hold up for a jury, either.

No matter how improbable, if there's a way for <whatever> to happen in the course of normal use, you have to design your bridge to accommodate it. (A 747 crashing into the bridge doesn't constitute normal use. An engineer may [should] simulate such an event to ensure the bridge responds in the safest possible manner, but at that point you've thrown out the expectation of maintaining structural integrity.)

Attornatus_Oregonensis
03-23-2008, 01:40 PM
There is a follow-up, of sorts, in today's O. Of note is:

"The Sellwood has had several load rating studies performed through the years, and those prompted weight restrictions since the 1980s."

So, as I was saying earlier, the structural issues have, over the past 20 years, prompted reductions in the weight of motor vehicles allowed on the bridge, but have not caused any reduction in bike or pedestrian use at all. In fact, I have been on the bridge during the Bridge Pedal twice when it was shoulder-to-shoulder all the way across. I'm pretty sure that if such use were a problem, the "several" load rating studies would have had something to say about it.

Link:

http://blog.oregonlive.com/breakingnews/2008/03/the_good_news_about_sellwood_b.html