Why Is the 520 Bridge So Expensive?

There's a webpage on the Seattle Channel about the 520 bridge. It's full of gross errors regarding the length of the bridge, depth of the water, etc. which I've address previously (they must have used the WSDOT 520 page as their source). I just loved this little blurb though:

University of Washington officials are considering asking state leaders for compensation for the disruption construction would cost their campus. They say fans may stay home from football and basketball games to avoid traffic issues.

What? It could have an adverse impact during construction on football games! Who needs the damn bridge anyway. But wait, there's more:

Did you know?
The state of Washington is home to many of the largest floating bridges in the world:
* SR 520 Evergreen Point Bridge
* I-90 Lacey V. Murrow Bridge - ... it sank ...
* I-90 Homer M. Hadley Bridge
* SR 104 Hood Canal Bridge - ... the bridge sank

To quote the famous line from "Python and the Holy Grail", Not Dead Yet!

TDM: Is Seattle Behind the Curve

Compared to Vancouver and Portland (especially Portland) it seems Seattle is more show than go.


TDM Encyclopedia

But hey, we've got Bike to Work Day. Better than a kick in the pants; no wait, maybe a kick in the pants is what we need.

WSDOT Reply About SR 520 Suspension Bridge

The first post to this blog was an email to WSDOT lead project engineers. Surprise! I got an answer. Unfortunately it only confirms my fear that nobody has seriously considered anything but another floating bridge. Here is the response I received and my reply:

February 3, 2009

Dear Bernie,

Thank you for writing the SR 520 Corridor Program regarding a suspension bridge alternative.

Early on during project planning, WSDOT considered a range of options for crossing Lake Washington, including replacing the SR 520 floating bridge with a suspension or truss bridge. WSDOT eliminated these bridge designs from consideration for several reasons, most notably lake conditions, cost, and size.

The physical characteristics of Lake Washington create challenges for supporting a suspension or truss bridge. These challenges include depth and a soft lake bed. The lake is very deep, at approximately 200 feet under most of the bridge. In addition, soft soils below the lake crossing make it extremely expensive and difficult to construct the large towers required to support a suspension or truss bridge.

Another cost prohibitive factor of building a suspension bridge across Lake Washington is the length. The bridge would have to span over 7,500 feet, making it the longest suspension bridge in the world. Today, the longest existing suspension bridge is the Akashi Kaikyo Bridge in Japan, spanning 6,527 feet. The Akashi Kaikyo Bridge took 10 years to build at a cost of $3.6 billion. The likely cost of a Lake Washington suspension or truss bridge would exceed $4 billion – the likely cost of the entire SR 520 corridor from Seattle to Bellevue Way.

Finally, the sheer size of the structure would have considerable impacts to views in the area. The towers supporting the main span would need to be about 900 feet tall, approximately 50% taller than the Space Needle. In addition, the two anchor piers required at the ends of the spans would be massive concrete supports.

The safer SR 520 bridges will be designed and built to:

• Have a 75-year design life;

• Withstand a 1000-year event earthquake; and

• Weather windstorms up to 92 miles per hour.

Please visit the project Web site for the latest news and information on the program.

Thank you again for your interest.

Sincerely,



Julie Meredith, P.E.

Program Director

SR 520 Corridor Program

http://www.wsdot.wa.gov/Projects/SR520Bridge

Dear Julie,

You have confused main span and bridge length in your analysis. The main span of the Akashi Kaikyo Bridge is 6,500 feet. The length of the bridge which includes the approaches on each side of the main towers is 12,831 ft overall. An engineering marvel to be sure!

An Evergreen Point suspension bridge would be very comparable the 8,000' Firth of Forth Roadway bridge in Scottland (main span 3,300') . This was constructed at the same time as the Evergreen Point Bridge but with a 120 year design life. The SR 520 crossing is much much closer in scope to the Tacoma Narrows than the Akashi Kaikyo. Even doubling the cost of that project we come in very close to the current estimates for another concrete raft and have an iconic structure that will last well into the next century.

Check again on the tower height. The WSDOT website says they would need to be 600', not 900'. That would put it right in line with other suspension bridges of that size. However, all of those bridges span shipping lanes and have twice the clearance the Coast Guard has approved for Lake Washington.

Look at the charts for Lake Washinton. The eastern tower would be in approximately 100' of water. On the western end there is an area which is 200' deep but it's not clear if this is where one of the towers would need to be located. Even if it is we solved that problem seventy years ago:

From the WSDOT website
http://www.wsdot.wa.gov/tnbhistory/Machine/machine2.htm
===============================
The Engineering Challenge in 1938

The Tacoma Narrows is a difficult place to build a bridge. The water is over 200 feet deep. Swift, treacherous tides moving at over 8.5 miles per hour (12.5 feet per second) sweep through the channel four times a day.
================================

There is no option uglier than paving the lake. Which bridge graces more picture postcards, Golden Gate or SR 520? The new roadway on stilts design I saw for keeping waves from breaking over the sides is even uglier, especially when viewed from lake level. Besides being a visual blight the two floating bridges cut up the lake detracting not only from the view but recreation. The current plans to provide mast clearance only at the eastern end will add two miles to the trip for sailboats moored at Leshi to get to Lake Union and the locks.

Bernie Hayden
Bellevue, WA

Bellevue City Council Eastside LINK Hearing

I attended the Bellevue City Council Eastside LINK hearing this evening. Boy did it run long, about 3 hours long. The vast majority of the comment was on segment B which runs through south Bellevue. "Votes" ran 10:1 against the Bellevue Way corridor and in favor of the BNSF route. I spoke in favor of keeping trains on train tracks. The Mayor even jotted down a note when I said that so if I hear it in a campaign speech I'm going to pull up the tapes of the meeting and file a copyright suit ;-) An official representative of the Bellevue Convention Center spoke earlier in the meeting and addressed concerns with one of the tunnel routes. I also made the point that the Seattle Convention Center already has a direction connection to the airport and that going forward Bellevue may have as much economic interest in linking to the City of Seatac as the City of Seattle. I also made the push for rail on the eastside serve the eastside and not be Seattle-centric as the current extend out from the existing LINK line in the International District is. That had been brought up earlier and was "seconded" by one of the speakers that followed. Hopefully that helped make that point sink in.

Boy did my speech suck. I think what I said was OK but the presentation sucked and there were points I didn't make or didn't make effectively. My tone of voice was squeaky and jilted. It was like I was suffering from stage fright. I didn't have prepared remarks but extemporaneous speaking is what I do best. Speaking at the end of a large group it was important that I not rehash what had been said so writing something in advance (oratory) would not have been the right answer but I should have had a notepad and made an outline before I went to the mic. Live and learn. On the plus side I did (again) finish well within my time limit. The whiners that go on and on saying "in conclusion" only after their red light's been on for a minute and the Mayor has to "chastise" them lose points in my book.

Now Read This

ESHB 3096 Clibborn, McIntire (C 270 L 08)
Financing the State Route Number 520 Bridge Replacement
Project - Establishes certain requirements for the design of the
replacement to the State Route 520(SR 520) bridge. Allows the
Washington State Department of Transportation (WSDOT) to seek
approval from the Legislature for the collection of tolls on the existing
and replacement SR 520 Bridge following the submission of the
tolling implementation report required by the act. Requires the
WSDOT to work with the Federal Highways Administration to
determine the actions necessary to toll the Interstate 90 Floating
Bridge. Establishes the State Route 520 Tolling Implementation
Committee to evaluate a variety of issues related to the tolling of the
SR 520 Bridge. Allows for the deferral of sales and use tax related to
the construction of the facility until five years after the opening of the
facility.

SHB 3224 Loomis, Hunter, Sells (C 127 L 08)
Reviewing and Conducting Studies on Providing Commuter Rail
Services - Directs Sound Transit to work in conjunction with the
Puget Sound Regional Council to analyze, and report to the
Legislature on whether commuter rail service between Eastern
Snohomish County and Eastern King County can be a meaningful
component of the region's future transportation system.

Concerning the Imposition of Tolls

As I read this summary of a bill past in 2008 tolls on the Evergreen Point floating bridge could not be used to fund the building of a new bridge. If you tear down your house it's considered new construction and treated very differently than improvements, preservation or maintenance.

Of course it's all a shell game since funding comes from the general fund and not from some "lock box" account for individual projects. At best this bill can mandate a minimum level of spending on a certain area in which the tolls are collected but that's unlikely to be much more than maintenance costs. Then again it provides no guidance as to what time frame the money must be spent so it could be never.

E2SHB 1773 Clibborn, Jarrett (C 122 L 08)
Concerning the Imposition of Tolls - Designates the Legislature as
the only entity with the authority to impose tolls on an eligible toll
facility, unless that authority is otherwise delegated. Requires all
revenue from an eligible toll facility to be used only to improve,
preserve, maintain, manage or operate the eligible toll facility on or
in which it is collected. Creates guidelines and requirements that the
Washington State Transportation Commission (WSTC) must follow
in determining toll rates. Requires any other entities seeking to
impose tolls to first seek approval from the Legislature for tolls on
state routes and from the WSTC for tolls or changes in tolls that
impact state routes. Requires the Washington State Department of
Transportation to use and administer toll collection systems that are
simple, unified, interoperable, and avoid the use of toll booths and to
set standards for all toll facilities in the state.