May I remind you, if a highway is shut down people will just drive more on other routes, often driving in modes that can create more CO2 relative to a constant driving speed.  The highways don't create CO2 emissions, the cars and people driving them do.  To suppose that people will have to take mass transit if a highway is shut down is not a very well-thought argument.  

If the elevated freeway is a main thoroughfare for intermodel trucks that service ships at the Port of Seattle, you might have a slightly valid point.  I'm sure the community leaders would be somewhat perplexed by lowering CO2 emissions by losing hundreds of millions in the shipping business, so I'd be real careful on that issue too.

As far as the highways, they are usually designed with a stated capacity in terms of thousands of vehicles per day, with many urban highways being over 125,000 trips.  An argument can be made that excess capacity, such as designing to 200,000 trips could increase CO2 in the future ... but again, that is a weak argument.  People drive because they have to get from Point A to Point B.  

Therefore, a case can be made that if people have to burn more fuel to get somewhere, since they have to take a longer or less direct route, CO2 would actually go up.  CO2 is a direct function of fuel carbon and the math is solid there.  It is all about the fuel and if one can save on fuel consumption.  The optimum speed for a vehicle is approximately 47.5 MPH.  

/sammie

Onward through the fog

... if a highway is shut down people will just drive more on other routes ...

That's true if and only if one assumes that the number of cars on the road is fixed and immutable. But why would you think that? It hasn't been the experience of other cities that have torn down highways. Turns out a lot of people formerly in cars will decide to use other means of transport, or carpool, or simply not travel at all. There's no law of nature that says the number of car trips can't be reduced.

To suppose that people will have to take mass transit if a highway is shut down is not a very well-thought argument.

Good thing nobody's making that argument! Of course people won't take public transport just because a freeway is gone. There are dozens of overlapping reasons people choose various transportation options.

No matter what alternative Seattle chooses, there's going to be an extended period of time when the highway isn't open. So the WA DOT has a plan to improve traffic management in other places, along with boosting public transportation. The argument of the surface-option crowd is: if you can make that stuff work, why not just make it permanent?

People drive because they have to get from Point A to Point B.

Talk about begging the question. What enviros and several local pols like Ron Sims are arguing is that the focus should not be on moving cars from place to place. The focus should be on moving people from place to place. What people desire is mobility; in some circumstances, cars are the easiest and cheapest form of mobility; in others, they aren't. The goal should be to make getting around the city easier without driving, rather than shaping the city to make driving easier.

grist.org

1. A seagull
   
2. An aquarium
   
3. The number 59
   
4. A football stadium
   
5. A baseball stadium
   
6. A metro bus
   
7. A bicyclist

BioD's rhetoric escapes me.  Not for the first time.

Plus, let us not overlook that row of sorry, neglected-looking trees, which could definitely use some loving.

DR has given us an excellent example of the misunderstood expression, "to beg the question."  Clearly, one should declare this elevated highway which enjoys its own Wikipedia site obsolete and closed to traffic (by the shadows cast, the photo was taken in early afternoon, and obviously does not get all that much use, by LA and Northeast standards), and go with the suggestion to get people who "have to go" (so they say) from Point A to Point B by some non-automobile means.

Meanwhile, just make sure that elevated road does not collapse, and build a park on top of it.  And an exciting village could grow up beneath.

On the other hand, let us hope that a six-lane highway down by the waterfront is not the best alternative.  That does not sound at all inspired, if the point is to attract pleasant waterside visits by tourists, and indeed by yourselves the not yet too bored citizens.  Philadelphia has something like that, down by the Delaware, and you do not want to resemble Philadelphia, do you.  No, I did not think so.

But whatever, it is your city.  Yours, and the seagulls', and the captive trees', and the orcas', etc.

As for those three hideous asteroid-sized mollusks, with, as it were, combs in their hair, those architectural monstrosities, they should be permitted to dominate your skyline no longer.  That would be just too cruel.  You have your children to consider, for one thing.  Either shoot those things to the dark side of the Moon, where they will no longer be seen by anyone with any sensitivity; or sink them in the ocean, ditto-wise, in the hope that they might become coral-reef-o-ramas.  Better, in a few years, to dive down in a few years, and see how happy that little fish family is, snugly residing in Seats NW EE 39 and 41.

Chickens deserve our true friendship! So do fish! So do other sentient beings! Let us learn to be kind.

I'm not going to go on the defensive and demand your facts, but I don't see any cities in the US having lower vehicle traffic and congestion because they didn't build any highways ... and I can't think of any major cities that ripped up a major old highway and threw it away without building something new.  

I can list a whole bunch of cities that went into light rail and got burned, or generalize about how HOV lanes are a waste of asphalt.  That obviously would not be popular topics here.  

But Grist also has been very negative about ethanol and bio-diesel, which are major environmental issues even if they are not perfect.  I think you folks are as guilty as I am - telling too much truth at the wrong time.  /sammie

Onward through the fog

Because I do, constantly. Traffic
is caused by the single car driver.

single people
get in their cars every morning.

They drive and wonder why
there's gridlock.

This is what I've been working on.
If you had a supertrain...

...you give people a reason to get out
of their cars. Coffee, great music...

...they will park and ride.
I know they will."

"But I still love my car, though."

It is all about the fuel and if one can save on fuel consumption.  The optimum speed for a vehicle is approximately 47.5 MPH.

If you mean the most fuel-efficient speed, for cars it is generally around 34 MPH. Fuel consumption at idle correlates-positively with the most-fuel-efficient speed -- so V8-powered cars typically have higher optimum-speeds, and 4-cylinder cars typically have lower optimum-speeds.

Some test numbers:
hybridcars.com/gas-mileage-factors/aggressive-driving-and-gas-mileage.html

The most dramatic comparison in the multi-vehicle DOE study was analyzing the differences between the Toyota Prius--the quintessential hybrid--and the Jaguar XJ8, a high-performance vehicle. To establish a baseline for efficiency, the DOE researchers searched for the speed at which each vehicle was the most efficient. They used a treadmill-like device called dynamometer to run the vehicles at a constant speed for 30 continuous minutes. The most efficient speed for the Toyota Prius was 20 mph, and its least efficient level was 70 mph.

Results for the Jaguar were the opposite. At a constant speed of 20 mph, when the Prius obtained a fuel economy of over 140 mpg, the Jaguar was recorded at a level of 37 mpg. Every additional 10 mph helped the Jaguar's efficiency until it reached its peak of 40 mpg at 50 mph. Duoba said, "Because the Jaguar is so inefficient at low speeds, you have to drive faster to improve its fuel economy."

But even in eco-friendly Austin, it was hard to get people out of their cars.  Even with free vans, gasoline stipends, and all kinds of media, the system did not do very well.  Maybe up in Seattle, a city known for more progressive attitudes, it would work better.  /sammie

Onward through the fog

No doubt the transportation needs and uses are quite different.

The Wikipedia article on Seattle has a lengthy section on transportation, including this interesting detail:
<<
A monorail line constructed for the 1962 Exposition still exists today [duh!, why is that supposed to be miraculous, as though it were comparable to the ancient aqueducts still bringing water to the city of Rome?] between Seattle Center and downtown and is used by tourists and by commuters from the north, who often find it cheaper to park at Seattle Center and take the 1 mile route to work rather than taking their car downtown. On November 26 2005 the monorail's two trains collided on a curve near Westlake Center where a design flaw made it impossible to pass safely. Service was suspended for a few months as both trains were repaired. The system then resumed operation.
>>

So even in the face of design flaws and collidability, many of the valiant citizens of the Emerald City are willing to park-and-ride.  It is in Wikipedia, so it must be true.  "We're not in Kansas anymore, Toto!"

KMannle, thank you for this literary offering.  It does not quite work as a poem, but as a song lyric it has promise.  You can ask BioD for further insight into this, who is of course a connoisseur of these matters, but it strikes me that the concept of the "single person" in a car comes across as kind of sexy, in American pop culture.

I love: "They drive and wonder why / there's gridlock."  What they really want to be thinking about is loinlock, and gridlock is just a futile distraction.

Or so I am told.

Chickens deserve our true friendship! So do fish! So do other sentient beings! Let us learn to be kind.

In 2000 the Greater Puget Sound population was 1 million...now it's 1.8 million.   I don't care how efficient your transportation system is, that's just too many people.

I would prefer whatever solution makes the traffic situation even more miserable and slows down commutes by a factor of 4.   At that point, perhaps the 0.8 million newcomers can be persuaded to leave.

I have been suggesting Lexington, KY where beautiful 3-bedroom houses can be found at an average price of $125,000.

Seattle is just not a place to be any more.   I think a FILO queing is the best way to deal with it (First In, Last Out).   Since I moved here in 1986, I expect at least a million or so of you others will have to exit by the time they draw my lottery number.

I happily love my bike or walking.

... shoot those things to the dark side of the Moon, where they will no longer be seen by anyone with any sensitivity ...

A well-lit farside picture: http://apod.gsfc.nasa.gov/apod/ap070225.html

--- G. R. L. Cowan, former hydrogen-energy fan
Oxygen expands around boron fire, car goes

with all due respect, experience as a transportation planner is not a qualification for  good urban design in the twenty-first century. Domination of urban infrastructure by the unbalanced hegemony of transportation planning is what has got us into this mess.

I don't see any cities in the US having lower vehicle traffic and congestion because they didn't build any highways ...

but we do see plenty of major cities that have failed to relieve congestion no matter how much blacktop they lay down. Atlanta, anyone?

and I can't think of any major cities that ripped up a major old highway and threw it away without building something new.  

More power to Seattle then to try something that is not a proven failure.

I can list a whole bunch of cities that went into light rail and got burned, or generalize about how HOV lanes are a waste of asphalt.  That obviously would not be popular topics here.

Actually I agree. Light rail as retrofit is clearly problematic - it has been been successful in the past (Chicago, Philadelphia) where they went in in advance of the suburbs and were instrumental in their formation. And HOV lanes - don't get me started about HOV lanes....

The critical mistake, as DR has already pointed out above, is assuming that current volumes of transportation activity are necessary to the ongoing economic vitality of a city and the well-being of its residents. Enabling the resolution of immediate locational conflicts (live on this side of town, work way the other side, take your kids to school somewhere else, find retail and cultural resources somewhere else again) by means of cross-town expressways simply allows people to run themselves ragged while destroying the very thing they love with pollution and noise. Public policy can do better.

The true meaning of life is to plant trees, under whose shade you do not expect to sit.