Thursday, October 06, 2005

It's a two bridge day.

I-90 isn't the only bridge looking at having work done, as I'm sure you have heard. SR-520, the other bridge over Lake Washington, is close to the end of its operating life, and desperately needs to be replaced. There are two options: one to replace the structure as it stands, a four lane bridge, and one to replace it with a six lane bridge, "lidding" the Montlake and Capitol Hill communities it splits up with concrete tops to allow for park or road space overhead. An eight lane alternative was considered, but it would seriously overload I-5's ability to handle more traffic.

The outer lanes of the six lane alternative would be HOV only - making existing bus service across the bridge much more reliable, and eliminating dangerous merge situations that currently occur at the ends of the bridge. This would also reduce congestion by reducing not only the number of passenger vehicles in the regular lanes, but many of the slowdowns caused by vehicle merges as well. Sound Transit has made it clear that they want better bus access for the high ridership 545 route from downtown to Redmond (read: Microsoft), and have that service listed as "Bus Rapid Transit" in their long-range plans. It's also going to be possible to put light rail or monorail on the new bridge - the pontoons floating the roadway will be designed to accomodate rail service in the future.

There have already been a few open houses on the project, and more are expected next year. The Montlake Community Club has taken an active role in demanding strong environmental mitigation, good HOV service and effective use of lid space for commuter services. A bicycle path attached to the alignment is assured - the number of bicycle commuters is very high from Seattle to Bellevue, and racks on buses are often full already - this has even led to Sound Transit installing three-bicycle racks on their coaches.

Funding for this project will likely come from three sources: The Washington State Legislature, King County voters, and tolls collected after the new bridge is constructed. For regular users, an electronic system of tags and overhead readers will be used to keep drivers from having to slow down at all - eliminating tollbooth stops for commuter travel.
Currently, $700 million is expected to come from tolls, and $500 million is set aside from the 2005 Transportation Package. Guess what little initiative will derail the replacement for at least another year? You guessed it - I-912.

8 Comments:

At 11:33 PM, Anonymous EvergreenRailfan said...

Well, an 8-lane 520 bridge could still be a possibility, if in November Irons gets elected. He sounds like he is pro-roads and buses and anti-rail. We need options, and must put in the ability for Light Rail to be there at a future date. They want more lanes on the freeways that feed into the SR520, then make it mandatory that right of way is preserved for rail based transit. Have all new lanes be tolled as well. It is about time automobiles paid their own way.

There are those that think just because we have become auto-dependent, we have to continue to have our transportation syatems revolve around the automobile. Light Rail should better yet be part of any future improvements to I-90, I-405, and I-5. Have the median widened to add room for Light Rail. We need to have the Right of Way banked for future use.

 
At 9:03 AM, Blogger Ben Schiendelman said...

The problem is, regardless of who is elected, WSDOT won't let an 8-lane bridge be built without a lot of upgrades for I-5 to handle it. Remember how bad the stretch between 520 and downtown is (southbound) - even with six lanes, that will probably get worse. The land up the hill from I-5 is extremely unstable as well, so shoring would probably have to take place (and that could mean home demolitions) before I-5 could get much wider.

 
At 12:33 PM, Anonymous EvergreenRailfan said...

Remember Kemper Freeman's proposal last year, he would pay for Improving I-5 and other projects by re-directing 10 cents of the existing gas tax towards Puget Sound congestion improvements. Building more Freeway Capacity has failed, it just keeps getting worse. Transit should have the parity it needs. The alternatives have to be there or we will be condemmened to repeat the cycle of endless traffic congestion and sprawl.

 
At 3:02 AM, Anonymous Jonathan said...

First--HOV lanes on the outside are a horrible, horrible idea. You should NEVER mix traffic doing 70 MPH with traffic merging on to a freeway at 45-50 MPH.

HOV drivers should be able to do 90 on the road without having to worry about anyone trying to get on to the freeway.

Second--there are two factors at work in making 5 such a mess. The first is that most interchanges and exit ramps were designed improperly to begin with. The 520 merge onto the left side of the freeway is a nightmare and is one of the reasons why 5 is always congested in the vicinity of Mercer St. I can point out a similar example every couple of miles. The curve under the Convention Center is another good example. Seattle is the only city in the entire country that has a blind turn on a freeway in a downtown area.

Third--5, 405, and 520 are carrying more traffic than they were designed for. Period.

Asserting that building more freeway capacity is useless is, frankly, crap. Some segments of Seattle freeways are carrying more cars than they realistically can. The remainder gets tied up because of inappropriate access ramps.

(and for the record, I want 12-lane freeways *and* six light rail lines from downtown to various parts of the city. I'll be adding articles about just such.)

 
At 3:02 AM, Anonymous Jonathan said...

First--HOV lanes on the outside are a horrible, horrible idea. You should NEVER mix traffic doing 70 MPH with traffic merging on to a freeway at 45-50 MPH.

HOV drivers should be able to do 90 on the road without having to worry about anyone trying to get on to the freeway.

Second--there are two factors at work in making 5 such a mess. The first is that most interchanges and exit ramps were designed improperly to begin with. The 520 merge onto the left side of the freeway is a nightmare and is one of the reasons why 5 is always congested in the vicinity of Mercer St. I can point out a similar example every couple of miles. The curve under the Convention Center is another good example. Seattle is the only city in the entire country that has a blind turn on a freeway in a downtown area.

Third--5, 405, and 520 are carrying more traffic than they were designed for. Period.

Asserting that building more freeway capacity is useless is, frankly, crap. Some segments of Seattle freeways are carrying more cars than they realistically can. The remainder gets tied up because of inappropriate access ramps.

(and for the record, I want 12-lane freeways *and* six light rail lines from downtown to various parts of the city. I'll be adding articles about just such.)

 
At 3:03 AM, Anonymous Jonathan said...

First--HOV lanes on the outside are a horrible, horrible idea. You should NEVER mix traffic doing 70 MPH with traffic merging on to a freeway at 45-50 MPH.

HOV drivers should be able to do 90 on the road without having to worry about anyone trying to get on to the freeway.

Second--there are two factors at work in making 5 such a mess. The first is that most interchanges and exit ramps were designed improperly to begin with. The 520 merge onto the left side of the freeway is a nightmare and is one of the reasons why 5 is always congested in the vicinity of Mercer St. I can point out a similar example every couple of miles. The curve under the Convention Center is another good example. Seattle is the only city in the entire country that has a blind turn on a freeway in a downtown area.

Third--5, 405, and 520 are carrying more traffic than they were designed for. Period.

Asserting that building more freeway capacity is useless is, frankly, crap. Some segments of Seattle freeways are carrying more cars than they realistically can. The remainder gets tied up because of inappropriate access ramps.

(and for the record, I want 12-lane freeways *and* six light rail lines from downtown to various parts of the city. I'll be adding articles about just such.)

 
At 2:41 AM, Anonymous EvergreenRailfan said...

HOV lanes on the outside, in the case of SR520 are a bad idea. They further erode a lack of breakdown shoulder capacity on SR-520. I was out on 167 last night, and a problem on the van happened and had to pull over to fix it, and we were in the carpool lane, which is on the inside, and we had to cut over 3 lanes of traffic to get to the shoulder.

Also, the interchanges for these freeways take up a lot of land. Interchanges for rail lines are different. I have seen where two BNSF lines converge. I have seen Black River Junction in Tukwilla, and the spot in Auburn where the Stampede Pass line converges on the North-South Main. They do not take up too much land.

 
At 3:08 AM, Anonymous Jonathan said...

Gah, sorry for the triple post. I was having problems with blocked cookies in Mozilla and then apparently got a bit zealous when I didn't see why entry pop up (offscreen).

Points re: shoulder space are very good. One of the things that goofs 520 so bad is that any diasbled vehicle blocks at least 33% of the road.

I'd like to see enough land acquired to leave 520 with a breakdown lane along the way to the bridge. Also because the rich folks in this city have consistently avoided losing any of their neighborhoods to freeway development. It's time for them to pony up. ;)

Re: freeway/rail interchanges, well I wasn't really addressing space requirements bewteen the two. There's enough space at every freeway interchange here to redo them with modified trumpet or T interchanges, if not a proper stack (that might be sticky).

I'm just disturbed by the whole idea of WSDOT saying "We can't do an 8-lane 520 because we don't want to improve the 5->520 interchange"--and when you *really* press them on the subject, they eventually break down from "can't afford it" to "don't really want to".

It's exactly that kind of thinking that limits the benefit of replacing the bridge at all if that interchange isn't dragged out of the 1960s. Not to mention that their plan will burn through $2 billion to just add a HOV lane in each direction. No additional general purpose lanes, no real provision for light rail, etc etc.

It's also exactly the kind of thinking that got us into this mess to begin with. I do not believe that any coordination between road projects is actually addressing the big picture (or really even happening. No one on the 520 project I've spoken to has any clue about what might be/is being/isn't being done on 5 or 405).

But I rant.

 

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