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I-345

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Alex Rodriguez
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I-345

Postby Alex Rodriguez » 17 Oct 2017 14:28

This thread on the old site prolly had 50+ pages, shocked there isn't already one on here. Anyway, city voted to begin a study to either bury, or remove I-345.

https://www.dallasnews.com/opinion/comm ... ghway-time

I've been in the bury camp since the beginning. Totally great with burying it, tunnelling it, would make it like the Big Dig in Boston or at least like Klyde Warren park. Would open up tremendous opportunities up top on repurposed land.

Think it is a terrible idea to rip out a 2 mile stretch of one of the biggest Interstates in the state of Texas and just hope 200,000 cars a day figure it out on surface streets/alternate routes. Yes yes, technically I345 only connects US75 to I45, but its basically 6-8+ lanes from Galveston to near the Oklahoma state line, unbroken, contiguous freeway.

Nobody in their right minds tears down a section of one of the biggest freeways in the state of Texas and hopes 200K cars just magically figure it out over time. It will be a parking lot nightmare right in the middle of Downtown Dallas. Dallas is only growing. And I'm on here advocating for D2, for Cotton Belt for HSR, so don't accuse me of loving the 1950s freeway mindset, I realize its a different time.

Bury it, I think that is a great idea, its the best solution for everyone.

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Re: I-345

Postby DPatel304 » 17 Oct 2017 14:38

Burying it seems insanely expensive, but the only realistic option, in my opinion. People always make the argument that, if you remove roads, traffic is decreased and drivers simply adapt. I think that works for smaller roads, not something as significant as I-345.

From what I understand, the Big Dig was similar (as you noted), but wasn't that an extremely expensive and unpopular project? The end result is beautiful, but it sounds like it probably wasn't worth the cost?

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Alex Rodriguez
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Re: I-345

Postby Alex Rodriguez » 17 Oct 2017 14:45

The Big Dig was a much more complicated project than what this would be. Not only did they have to bury all of the freeway in the North End but they built a tunnel underwater, under the Boston Main Channel, to Logan Airport. Much more linear mileage, and obviously tunnelling under basically the ocean. Additionally the North End is much more dense than anything surrounding I-345.

It will probably be a $2 Billion dollar or so project to do I-345 but I don't see how you don't spend the money, otherwise I think you basically ruin downtown with traffic.

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Re: I-345

Postby DPatel304 » 17 Oct 2017 14:51

I'm not too familiar with the Big Dig project, so thanks for elaborating.

Even though both the Big Dig and, to a lesser degree, this I-345 burial are extremely expensive projects, I'm 100% for them. Not only would this connect Deep Ellum and Downtown, but now all of a sudden you don't have any highway separating Downtown from most of East Dallas. Ross Ave can truly become a great connector between Downtown and the Lakewood area, and I could see a lot of these becoming more bike/walk friendly.

I'm not too concerned about the extra land that this highway would free up. I think there is still plenty of land in the CBD, but I'm really excited about how much this would open up our Downtown area. Right now it's completely boxed in by highways, which is probably limiting development quite a bit.

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tanzoak
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Re: I-345

Postby tanzoak » 17 Oct 2017 15:16

It's not "just hoping" that they will find alternate routes. It's a TxDOT study. A study from the Texas highway people. They don't just guess, they build out models and run simulations and do all kinds of stuff. And again, from the Texas highway people, so any bias to the model is likely to be in favor of more highways reducing delay.

They found essentially no congestion difference between the three options.
Hours of delay in 2040:
Tear Down - 163.8k
Lower - 163.1k
Replace - 161.3k

I know it doesn't feel intuitive, but it's a similar thing to how removing links can actually reduce delay depending on the characteristics of the network. The process of individuals minimizing personal travel times can result in higher system-wide travel times compared to a system that makes a minority of people slightly worse off to the benefit of system performance as a whole.

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Tivo_Kenevil
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Re: I-345

Postby Tivo_Kenevil » 17 Oct 2017 15:38

Based on the numbers from above. I say Tear it TF down.

I would even go further and say why not just close 345 for 6 months to test.

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Alex Rodriguez
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Re: I-345

Postby Alex Rodriguez » 17 Oct 2017 16:12

If you can post the URL for that study, I'd like to see it. I think the name "Link" is technically accurate, but in practice not at all what I-345 is. It is a 2 mile section of one freeway named I45/US75. You are tearing down the middle of a freeway, period. I don't understand the resistance to burying or tunneling other than not wanting to spend the money to do this right. Propose a nominal, low end toll like 50 cents and it pays for itself. Because if you tear down:

*If you are wanting to travel to anywhere on US75 from north of that point to near 635, you will have to take a surface street through Downtown to 75, a surface street through the proposed urban millennial utopia, I30 to Woodall Rogers and sit in a nightmare, or go all the way East 635 which is a nightmare today. Or 30 to 35 to DNT and wait 45 minutes to get through the 1 lane on ramp to DNT. Or some other alternate surface street.

*If you want to get to points north of LBJ you could take same nightmare East 635 or go 30 miles out of your way to get on the George Bush. Or same terrible options already described.

There is no good option. Its not a matter of feeling intuitive. Its looking at the system of roads and determining where you fit 200K cars.

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electricron
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Re: I-345

Postby electricron » 17 Oct 2017 16:57

The problem with tunneling I-345 is that I-30 is already 25 feet below grade. So to tunnel under I-30 will require tunneling I-345 50 feet below grade. Presently, at I-30, I-345 (or US-75) is 100 feet above I-30 or 75 feet above grade. So you will have to change it’s elevation by 125 feet.
The steepest Interstate Highway grade in the entire country is 4% between Golden and the Eisenhower Tunnel in Colorado on I-70. That means for every foot in elevation change, it needs 25 feet horizontal travel. So to achieve a 125 feet elevation change on I-345, you’ll need to rebuild 25 times as much highway on both sides, 3,125 feet in each direction, a total of 6,250 feet. Then you would have to include on both sides a tractor-trailer pull over ramp just as long so these semis can perform the legally require brake checks, the City of Dallas would have to change it’s local law outlawing engine braking. I’m not sure how steep a grade is allowed before brake check testing isn’t required by law? Whatever it is, it’lll probably double the horizontal distance of the elevation changes needed.
I’m not going to suggest it’s an impossible engineering task to realign I-345, I will suggest it will be very expensive.

There’s been talk about relocating or rerouting I-30 around south Dallas. If that were to occur first, or at the same time changing the I-345 elevation, I-345 could fit in at the elevation I-30 uses today - just 25 feet below grade in an open trench, vs in a tunnel 50 feet below grade. That would significantly change its design and costs.

I suggest we delay designing and planning what to do with I-345 until after we decide what to do with I-30.

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tanzoak
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Re: I-345

Postby tanzoak » 17 Oct 2017 17:03

Alex Rodriguez wrote:If you can post the URL for that study, I'd like to see it.


Here is the overview: http://www.dallascitymap.com/CityMAP_Br ... ressed.pdf
Here is the full study: http://www.dallascitymap.com/DallasCity ... ressed.pdf

I think the name "Link" is technically accurate, but in practice not at all what I-345 is. It is a 2 mile section of one freeway named I45/US75. You are tearing down the middle of a freeway, period.


Apologies for using the technical term where the meaning might not be clear. "Link" is just a transportation engineering term for section of roadway. It doesn't imply anything about its use or importance. (The other component of a network is a "node," where links intersect).

I don't understand the resistance to burying or tunneling other than not wanting to spend the money to do this right. Propose a nominal, low end toll like 50 cents and it pays for itself. Because if you tear down:

*If you are wanting to travel to anywhere on US75 from north of that point to near 635, you will have to take a surface street through Downtown to 75, a surface street through the proposed urban millennial utopia, I30 to Woodall Rogers and sit in a nightmare, or go all the way East 635 which is a nightmare today. Or 30 to 35 to DNT and wait 45 minutes to get through the 1 lane on ramp to DNT. Or some other alternate surface street.

*If you want to get to points north of LBJ you could take same nightmare East 635 or go 30 miles out of your way to get on the George Bush. Or same terrible options already described.



The resistance to lowering compared to tear down comes from a) the higher construction cost (and you can't add tolls b/c it's an interstate), b) the ongoing cost of lost potential tax revenues, both from land that is not available to be developed and the reduction in value of the land immediately adjacent to the highway, c) additional noise and air pollution compared to boulevard, and d) a preference for a connected downtown and Deep Ellum and the more urban, pedestrian, and transit-friendly environment that connection allows.

The concern about surface streets being overwhelmed has some basis, as the percent of the total delay that occurs on city streets would increase to 40% in the tear down scenario vs 32% in below-grade.

That said, the slight increase in congestion is a price worth paying for the benefits conferred by a tear down.

Tunneling is not being considered at all due to extreme cost.

There is no good option. Its not a matter of feeling intuitive. Its looking at the system of roads and determining where you fit 200K cars.


I agree that it is about looking at the road network and seeing how people will get from one point to another. That's exactly what TxDOT did, in a systematic way with an actual network and traffic model, not just a layman's eyeball and intuition. They found a limited increase in delay for the tear-down option compared to the alternatives.

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Re: I-345

Postby jeremysmith214 » 17 Oct 2017 18:28

In the prior post, I received backlash for saying that the cost can be minimized by encouraging a toll company to simply make it underground and run it as a toll.

If the cost are still relatively high, the City of Dallas could also possibly add a specific target on the area that capitalize on the new development to also help pay toward the cost along with a toll company building it.

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Alex Rodriguez
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Re: I-345

Postby Alex Rodriguez » 17 Oct 2017 20:01

Tanzoak, thanks for the info and thoughtful response. Like JeremySmith says, I think a toll is a real option to pay for it. 635 and 35 both have a toll component now, no reason why a tunnel or below grade 345 couldnt have some type of toll component.

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Re: I-345

Postby Alex Rodriguez » 17 Oct 2017 20:24

electricron wrote:The problem with tunneling I-345 is that I-30 is already 25 feet below grade. So to tunnel under I-30 will require tunneling I-345 50 feet below grade. Presently, at I-30, I-345 (or US-75) is 100 feet above I-30 or 75 feet above grade. So you will have to change it’s elevation by 125 feet.


What about not starting the descent into the tunnel configuration until after the I-30 flyover?

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tanzoak
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Re: I-345

Postby tanzoak » 17 Oct 2017 21:03

Alex Rodriguez wrote:Tanzoak, thanks for the info and thoughtful response. Like JeremySmith says, I think a toll is a real option to pay for it. 635 and 35 both have a toll component now, no reason why a tunnel or below grade 345 couldnt have some type of toll component.


You can't toll existing lanes on an interstate (literally against the law). The tolled lanes on 635 and 35 are new lanes from highway expansions, which isn't on the table for 345.

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Tucy
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Re: I-345

Postby Tucy » 17 Oct 2017 22:22

tanzoak wrote:
They found essentially no congestion difference between the three options.
Hours of delay in 2040:
Tear Down - 163.8k
Lower - 163.1k
Replace - 161.3k
.


NM

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Alex Rodriguez
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Re: I-345

Postby Alex Rodriguez » 18 Oct 2017 08:06

I reviewed the document http://www.dallascitymap.com/DallasCity ... ressed.pdf, and the Remove Scenario numbers come out even with the other 2 scenarios after you rebuild the entire Downtown Dallas Freeway system. That is more of a pipe dream than burying I-345. Why? See Page 191 and 193, but here is a quick recap...


First of all you have to build the Trinity Parkway, which isn't happening now. I quoted two different sections on Trinity Parkway below. Second of all you have to rebuild I-30, tear down part of I-45 and rebuild to surface streets, and rebuild Woodall Rogers. Then major projects at Good Latimer and Cesar Chavez.

Well great, that is easily double or triple the cost of simply burying I-345, but if the land on top is worth that much $$$, then I guess let's spend 10-15 years and $5+ Billion to do this scenario.

So, to summarize, if you don't rebuild the entire Dallas Freeway system, then tearing down I-345 is exactly what I've already said which is a total traffic nightmare. You've got to put 200K cars a day somewhere and the remove scenario here puts them on a completely rebuilt Dallas Freeway system. If you don't rebuild I-30, SH366, I-45, AND build the Trinity Parkway, its basically traffic chaos to remove I-345.



1. "It is noted that the I-345 Remove Scenario includes the proposed Trinity Parkway in the configuration currently endorsed by the City of Dallas. This is a new 4-lane toll road between I-45 at US 175 and I-35E at US 183."

2. Woodall Rodgers / US 75 would be rebuilt to remove the interchange and build it as a through route. "Woodall Rodgers, already carrying more traffic than its capacity, would carry less traffic with the
scenario. This reduction may be more attributable to the different Trinity Parkway Access Configurations in the plan and the scenario".

3. REMOVE I-45 north of Martin Luther King, w I-45 main lanes going to and from Cesar Chavez Drive and with ramps to and from Good Latimer Expressway.

4. Rebuild I-30 per PROJECT PEGASUS

5. Realign Good Latimer the DART grade crossing and Al Lipscomb Way. S.M. Wright.

6. Cesar Chavez Boulevard/I-30 Interchange rebuilt in a diamond configuration.

7. Cesar Chavez interchange with US 75.

8. A laundry list of minor stuff.

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Re: I-345

Postby jeremysmith214 » 18 Oct 2017 09:16

tanzoak wrote:
Alex Rodriguez wrote:Tanzoak, thanks for the info and thoughtful response. Like JeremySmith says, I think a toll is a real option to pay for it. 635 and 35 both have a toll component now, no reason why a tunnel or below grade 345 couldnt have some type of toll component.


You can't toll existing lanes on an interstate (literally against the law). The tolled lanes on 635 and 35 are new lanes from highway expansions, which isn't on the table for 345.


There is probably a work around this particular law essentially if the interstate is actually torn down and no longer exist essentially becoming tunneled.

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tanzoak
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Re: I-345

Postby tanzoak » 18 Oct 2017 10:21

Alex Rodriguez wrote:I reviewed the document http://www.dallascitymap.com/DallasCity ... ressed.pdf, and the Remove Scenario numbers come out even with the other 2 scenarios after you rebuild the entire Downtown Dallas Freeway system. That is more of a pipe dream than burying I-345. Why? See Page 191 and 193, but here is a quick recap...


This is not the "gotcha" you think it is because all of the other I-345 alternatives also assume these other projects are done as well.

That's the whole point of this kind of alternative analysis, to isolate the impacts of one particular project.

So yes, they estimate that delay will significantly increase without these other projects (to 272.5k). But they think that's true regardless of what is done to I-345. Notably, that 272.5k estimate is calculated with a straight unmodified rebuild of I-345.

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Re: I-345

Postby muncien » 18 Oct 2017 10:59

If even half of those cars currently using I345 are forced around the mix master, or through city streets, this area will become a traffic hell that will severely impact those very people who live/work there. As opposed to now, where it's only a little bit of a traffic hell, and its almost completely unnoticeable by those below.
What is now considered a 'dark and kinda creepy walk' (actual words by local), will undoubtedly become a game of frogger with locals having to navigate at grade through cars simply rushing to pass through... Sure, it'll be on a tree lined boulevard, but a nightmare no less. If the locals though an at grade D2 would disrupt traffic flow around Good Latimer, than an I345 tear down would dwarf that easily.
I know Kingston will simply say I don't understand traffic engineering or whatever, but I used to walk this are all the time and I do have common sense. A cut/cap tunnel (tolled or otherwise) from Canton to Ross would make the most sense. That's not even close to the same level of complexity, engineering, or cost of the big dig.
But, they better get the plan coordinated with D2 sooner rather than later.
"He doesn't know how to use the three seashells..."

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tanzoak
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Re: I-345

Postby tanzoak » 18 Oct 2017 11:08

jeremysmith214 wrote:There is probably a work around this particular law essentially if the interstate is actually torn down and no longer exist essentially becoming tunneled.


Unfortunately, there isn't. What *would* allow tolling is removal of that roadway from the interstate highway system. However, then the state would be fully on the hook for paying for maintanence, of which the feds currently pay 90%.

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Re: I-345

Postby DPatel304 » 18 Oct 2017 11:09

So, for vehicles that are simply passing through DFW, does it make sense for them to go from 45->20->635->75? According to Google Maps, that would be an additional 7.6 miles, but if you're a truck driving across the country, would those 7.6 miles make that much of a difference?

I don't know what the traffic is currently like on these highways, so this might be a dumb suggestion, but I'm just thinking of ways we can divert the traffic from those who are simply passing through. Then perhaps we can get an idea as to how many people actually require I-345.

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Alex Rodriguez
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Re: I-345

Postby Alex Rodriguez » 18 Oct 2017 11:50

tanzoak wrote:
Alex Rodriguez wrote:I reviewed the document http://www.dallascitymap.com/DallasCity ... ressed.pdf, and the Remove Scenario numbers come out even with the other 2 scenarios after you rebuild the entire Downtown Dallas Freeway system. That is more of a pipe dream than burying I-345. Why? See Page 191 and 193, but here is a quick recap...


This is not the "gotcha" you think it is because all of the other I-345 alternatives also assume these other projects are done as well.


That is not the case. Review the Scenario Descriptions for each Scenario on pages 187, 191, and 194. They are not all the same. The Modify Scenario obviously has the fewest additional changes required. The Below Grade Scenario has some significant interchange rebuilds at 75 and 30. The Teardown Scenario has the Trinity Parkway buildout, the I-30 Project Pegasus, the removal of I-45, the 366/75 rebuild.

Maybe page 194 is confusing, its the Below Grade Scenario Description and it mentions the Trinity Parkway also, but if you read it is also talking about the "Remove Scenario"

"It is noted that the I-345 Remove Scenario includes the proposed Trinity Parkway in the configuration currently endorsed by the City of Dallas. This is a new 4-lane toll road between I-45 at US 175 and I-35E at US 183."

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Tucy
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Re: I-345

Postby Tucy » 18 Oct 2017 12:00

Alex Rodriguez wrote:
tanzoak wrote:
Alex Rodriguez wrote:I reviewed the document http://www.dallascitymap.com/DallasCity ... ressed.pdf, and the Remove Scenario numbers come out even with the other 2 scenarios after you rebuild the entire Downtown Dallas Freeway system. That is more of a pipe dream than burying I-345. Why? See Page 191 and 193, but here is a quick recap...


This is not the "gotcha" you think it is because all of the other I-345 alternatives also assume these other projects are done as well.


That is not the case. Review the Scenario Descriptions for each Scenario on pages 187, 191, and 194. They are not all the same. The Modify Scenario obviously has the fewest additional changes required. The Below Grade Scenario has some significant interchange rebuilds at 75 and 30. The Teardown Scenario has the Trinity Parkway buildout, the I-30 Project Pegasus, the removal of I-45, the 366/75 rebuild.

Maybe page 194 is confusing, its the Below Grade Scenario Description and it mentions the Trinity Parkway also, but if you read it is also talking about the "Remove Scenario"

"It is noted that the I-345 Remove Scenario includes the proposed Trinity Parkway in the configuration currently endorsed by the City of Dallas. This is a new 4-lane toll road between I-45 at US 175 and I-35E at US 183."


I agree the report is confusing on that point. But you are clearly right that the Remove Scenario shifts the congestion and a huge amount of traffic from freeways to local streets and thoroughfares, including Elm, Commerce, Good Latimer and Cesar Chavez.

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tanzoak
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Re: I-345

Postby tanzoak » 18 Oct 2017 12:18

Alex Rodriguez wrote:
tanzoak wrote:
This is not the "gotcha" you think it is because all of the other I-345 alternatives also assume these other projects are done as well.


That is not the case. Review the Scenario Descriptions for each Scenario on pages 187, 191, and 194. They are not all the same. The Modify Scenario obviously has the fewest additional changes required. The Below Grade Scenario has some significant interchange rebuilds at 75 and 30. The Teardown Scenario has the Trinity Parkway buildout, the I-30 Project Pegasus, the removal of I-45, the 366/75 rebuild.

Maybe page 194 is confusing, its the Below Grade Scenario Description and it mentions the Trinity Parkway also, but if you read it is also talking about the "Remove Scenario"

"It is noted that the I-345 Remove Scenario includes the proposed Trinity Parkway in the configuration currently endorsed by the City of Dallas. This is a new 4-lane toll road between I-45 at US 175 and I-35E at US 183."


It actually is the case...

Image

*System for each scenario assumes the following projects or
operational improvements are constructed: Southern Gateway,
Lowest Stemmons, and Trinity Parkway 4 Lane 45MPH concept.

I can assure that that TxDOT/HNTB are not total idiots with no idea how to do their jobs. And can also assure you that if TxDOT were trying to pull a fast one, it wouldn't be deceit or bias in favor of *tearing down* a highway.

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Re: I-345

Postby tanzoak » 18 Oct 2017 12:33

muncien wrote:What is now considered a 'dark and kinda creepy walk' (actual words by local), will undoubtedly become a game of frogger with locals having to navigate at grade through cars simply rushing to pass through... Sure, it'll be on a tree lined boulevard, but a nightmare no less.


The overall impact on pedestrian experience would certainly depend on the design of the boulevard. If it looks like Northwest Highway, yeah that's not good at all.

But a) the configuration considered in the TxDOT study was for only 3 lanes in each direction, which while still large is just a normal Dallas street, and b) the city seems to be committed to the Dallas Complete Streets Design Manual era. Assumedly there will be plenty of stop lights and crosswalks. Not seeing "frogger."

The danger and unpleasantness to pedestrians doesn't come from traffic/congestion, but from travel speeds and other design factors. So just because there's increased congestion on surface streets, that doesn't mean it's a worse pedestrian experience on that front. (In addition of course to the aesthetics of walking amongst buildings instead of underpasses).
Last edited by tanzoak on 18 Oct 2017 12:44, edited 2 times in total.

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Alex Rodriguez
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Re: I-345

Postby Alex Rodriguez » 18 Oct 2017 12:35

tanzoak wrote:*System for each scenario assumes the following projects or
operational improvements are constructed: Southern Gateway,
Lowest Stemmons, and Trinity Parkway 4 Lane 45MPH concept.

I can assure that that TxDOT/HNTB are not total idiots with no idea how to do their jobs. And can also assure you that if TxDOT were trying to pull a fast one, it wouldn't be deceit or bias in favor of *tearing down* a highway.


OK so all the Scenarios assume:

* Southern Gateway - which is US67, and I-35 from 67 to the Trinity River - That is not relevant to this discussion.
* Lowest Stemmons - which is I-35 between 30 and Woodall Rogers - Not relevant to this discussion
* Trinity Parkway - Relevant.

Okay so I'll grant you that all three require Trinity Parkway. But that still leaves the Tear Down Scenario as requiring I-30 Project Pegasus, teardown of I-45 north of MLK to 30, rebuild and reconfiguration of Woodall Rogers and 75, and a bunch of work and interchanges for both Good Latimer and Cesar Chavez.

None of that are required for the other two options. I-30 Project Pegasus is the continuation of the Horseshoe project, that will be well north of $1 Billion just by itself. That and all the other work that applies ONLY to Tear Down option is required to get the numbers to look the way they do. Period.

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Re: I-345

Postby Alex Rodriguez » 18 Oct 2017 12:48

And by the way, I'm not saying that anyone is trying to pull a fast one. What I'm saying is that for each option to have basically the same traffic impact, per the report:

**Modify - you remove some ramps for CBD access
**Below Grade - Trench I-345, partial rebuild of I45 and 366/75 interchanges. Major work on Ross
**Tear down - I-30 Project Pegasus, Removal of I45 from MLK to 30 w/ Surface Street connections, Rebuild of 366/75, Major work on Good Latimer, Major work on Cesar Chavez.

If you do the above to each of the 3 options you end up with basically the same traffic numbers for the freeway system. The surface street traffic still goes up in the Tear Down option even in this report.

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Re: I-345

Postby tanzoak » 18 Oct 2017 13:07

Alex Rodriguez wrote:But that still leaves the Tear Down Scenario as requiring I-30 Project Pegasus, teardown of I-45 north of MLK to 30, rebuild and reconfiguration of Woodall Rogers and 75, and a bunch of work and interchanges for both Good Latimer and Cesar Chavez.

None of that are required for the other two options. I-30 Project Pegasus is the continuation of the Horseshoe project, that will be well north of $1 Billion just by itself. That and all the other work that applies ONLY to Tear Down option is required to get the numbers to look the way they do. Period.


You realize that the cost of all of those components are included in the estimated tear down cost, right? Like, yes, those things are part of the plan, you are correct.

I don't know why you think that TxDOT is making obviously false estimates and comparisons all as part of a crusade to tear down a highway. Spoiler alert: TxDOT thinks highway construction and expansion is the solution to most everything.

The I-345/I-45 Remove scenario entails removing the existing elevated
freeway and replacing it with a series of arterials that would free up previously
unavailable space throughout the corridor. The estimate includes the following:
1. Completely removing I-345 from I-30 to Woodall Rodgers Freeway as well
as I-45 from Martin Luther King, Jr. Blvd. (MLK) to I-30.
2. Reconstructing portions of Cesar Chavez Blvd., Good Latimer Blvd. and
reconstructing a new S.M. Wright Blvd. from Al Lipscomb Blvd. to north of
I-30. This new boulevard would generally follow the former I-45 corridor.
3. Reconstructing several east-west cross streets within the two corridors.
4. Constructing a new below grade highway section that extends to Central
Expressway (US 75) to Woodall Rodgers Freeway at Pearl Street.

The facility capital cost estimate for the I-345/I-45 Remove scenario is in the $100
- $499 million range.

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Re: I-345

Postby tanzoak » 18 Oct 2017 13:09

Alex Rodriguez wrote:And by the way, I'm not saying that anyone is trying to pull a fast one. What I'm saying is that for each option to have basically the same traffic impact, per the report:

**Modify - you remove some ramps for CBD access
**Below Grade - Trench I-345, partial rebuild of I45 and 366/75 interchanges. Major work on Ross
**Tear down - I-30 Project Pegasus, Removal of I45 from MLK to 30 w/ Surface Street connections, Rebuild of 366/75, Major work on Good Latimer, Major work on Cesar Chavez.

If you do the above to each of the 3 options you end up with basically the same traffic numbers for the freeway system. The surface street traffic still goes up in the Tear Down option even in this report.


Yes, that is correct. Those are the 3 projects.

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Re: I-345

Postby Alex Rodriguez » 18 Oct 2017 14:53

tanzoak wrote:
Alex Rodriguez wrote:But that still leaves the Tear Down Scenario as requiring I-30 Project Pegasus, teardown of I-45 north of MLK to 30, rebuild and reconfiguration of Woodall Rogers and 75, and a bunch of work and interchanges for both Good Latimer and Cesar Chavez.

None of that are required for the other two options. I-30 Project Pegasus is the continuation of the Horseshoe project, that will be well north of $1 Billion just by itself. That and all the other work that applies ONLY to Tear Down option is required to get the numbers to look the way they do. Period.


You realize that the cost of all of those components are included in the estimated tear down cost, right? Like, yes, those things are part of the plan, you are correct.


I-30 Project Pegasus is going to be $1 Billion just by itself. No way it is possibly part of $100-$499 Million estimate, its not even listed. And what is included in Woodall Rogers/Central because that mentions Pearl street. Hard to tell what exactly is covered by $499 million, that's nothing in today's freeway construction world.

Anyway, it will be interesting to see what comes of this new study. Hopefully they use a different methodology. The options need to be considered independent of prerequisites.

1. Tear down option should only include what is required to connect streets, move traffic off of I-45 to surface streets, tear down freeway, interchanges, redo Central to Woodall Rogers.
2. Below grade option should only include what is required to tunnel the road and rebuild necessary ramps to 30 and 75.

Obviously it will be cheaper to tear down. Obviously traffic will be way worse in tear down. Then you can look at things that need to happen to make the traffic situation bearable in a tear down. That would be project Pegasus for I-30. That would be redo of Woodall Rogers through Central. And all the side street work and arterial work. All of that is not going to be $499 Million. It's going to cost north of $2 Billion, or likely more than it will cost to tunnel I-345. Except if you spend $2 Billion on the tunnel, you haven't reduced the capacity of the system. That's why I'm for doing what Seattle is doing with Alaska Viaduct, right now. Below Grade is the way to go.

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Re: I-345

Postby tanzoak » 18 Oct 2017 18:43

Alex Rodriguez wrote:I-30 Project Pegasus is going to be $1 Billion just by itself. No way it is possibly part of $100-$499 Million estimate, its not even listed.


You are correct that $1 billion was the (2005) estimate of the entire Project Pegasus, which included the recently-completed Horseshoe project. I think you may have mixed up the estimate for the entire Project Pegasus with the estimate for the additional portion that is included in the tear-down alternative, which is indeed listed, it just isn't titled "Project Pegasus."

The Horseshoe Project is the most expensive component of Project Pegasus, and its final cost was $787 million.

The second component of Project Pegasus is the Lowest Stemmons project, which is included in the traffic analysis of all alternatives (and is therefore not included in any of the alternatives' cost estimates).

The last component of Project Pegasus, and the one that is unique to the tear-down alternative, is work on the I-30 Canyon portion to improve frontage roads and interchanges, which would be needed to provide adequate connection with the surface streets that would be expected to take a greater load. That component was estimated at $86-93 million in 2002 dollars.

The 2005 EA is here: http://www.projectpegasus.org/images/Pe ... 02_web.pdf
The 2002 tech memo is here: http://www.projectpegasus.org/images/ph ... chmemo.pdf

And what is included in Woodall Rogers/Central because that mentions Pearl street. Hard to tell what exactly is covered by $499 million, that's nothing in today's freeway construction world.


See pages 225-226 for map and description of what is included in the alternative.

Anyway, it will be interesting to see what comes of this new study. Hopefully they use a different methodology. The options need to be considered independent of prerequisites.

1. Tear down option should only include what is required to connect streets, move traffic off of I-45 to surface streets, tear down freeway, interchanges, redo Central to Woodall Rogers.
2. Below grade option should only include what is required to tunnel the road and rebuild necessary ramps to 30 and 75.



This is, in fact, what they did to develop the cost estimates.

For the delay estimates, they included Southern Gateway, Lowest Stemmons, and Trinity Parkway for all three. Maybe you would have preferred them to run the models as current + alternative or 2040_no_build + alternative instead of 2040_build + alternative, but regardless, all three alternatives are operating under the same conditions and assumptions.

I'm not sure why you think TxDOT and HNTB are unable or unwilling to correctly perform alternative analyses (and if they aren't, why TxDOT would bias it in favor of a highway tear-down).

Obviously it will be cheaper to tear down. Obviously traffic will be way worse in tear down. Then you can look at things that need to happen to make the traffic situation bearable in a tear down. That would be project Pegasus for I-30. That would be redo of Woodall Rogers through Central. And all the side street work and arterial work. All of that is not going to be $499 Million. It's going to cost north of $2 Billion, or likely more than it will cost to tunnel I-345. Except if you spend $2 Billion on the tunnel, you haven't reduced the capacity of the system. That's why I'm for doing what Seattle is doing with Alaska Viaduct, right now. Below Grade is the way to go.


Traffic will not obviously be way worse. I understand that intuitively it seems like it must, but it doesn't actually.

The models for this project predict that overall congestion won't increase that much, though a significant portion of that congestion will be transferred from highways to surface streets. I'm the first to say that the models aren't perfect. But for whatever their flaws, they perform much much better than eyeballed intuition.

Also, this kind of situation, with existing observed travel demand and flows, is where they perform best (as opposed to greenfield highway construction). And while model assumptions can be tweaked to favor a particular outcome, I simply do not believe that TxDOT is pushing assumptions that are biased in favor of a highway tear-down.

Lastly, as for the guesstimates about total costs.. Digging a giant trench is very expensive. As is building out full highway infrastructure. It simply does not compare to building surface roads and re-doing some exit ramps. Transportation infrastructure project costs are notoriously under-estimated, so it would not surprise me in the least to see a tear-down come in over this estimate. But that's the same for all projects.

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Re: I-345

Postby Alex Rodriguez » 19 Oct 2017 07:37

Let me fix this for you :P

tanzoak wrote:The models for this project predict that overall congestion won't increase that much, if at the same time you tear down I-345 you also rebuild every major freeway and street in the greater Downtown Dallas area, though a significant portion of that congestion will be transferred from highways to surface streets. I'm the first to say that the models aren't perfect. But for whatever their flaws, they perform much much better than eyeballed intuition.

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Re: I-345

Postby Alex Rodriguez » 19 Oct 2017 07:44

And kidding aside, thanks for bringing that study to the discussion. Good to see what the different options look like. This study only reinforces my original point, which is you don't just simply tear down I-345 and be done. Someone earlier in this thread said "Based on the numbers from above. I say Tear it TF down. I would even go further and say why not just close 345 for 6 months to test."


Well no, if you just tear it down, and do nothing else, its a traffic nightmare. The overall congestion won't increase that much if you tear down I-345, AND rebuild I-30, AND rebuild 366, AND CC AND GL AND every surface street between MLK and I-30.

DO ALL THAT and then the overall traffic doesn't increase that much. Yes I agree with that 100%.

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Re: I-345

Postby PonyUp13 » 19 Oct 2017 07:57

I believe a key part of Patrick's kennedy's original plan for removal (in addition to street-level boulevards) was the upgrades/completion of the Peak/Haskell, Hall, and Fitzhugh corridors to connect neighborhoods to the East to 75.

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Re: I-345

Postby tanzoak » 19 Oct 2017 09:28

Alex Rodriguez wrote:Well no, if you just tear it down, and do nothing else, its a traffic nightmare. The overall congestion won't increase that much if you tear down I-345, AND rebuild I-30, AND rebuild 366, AND CC AND GL AND every surface street between MLK and I-30.



Tbh, I'm not quite sure why you think the scope of the tear-down project is so massive, particularly in comparison to trenching. It's quite a bit easier to build some surface streets and reconstruct a short portion of an above-grade highway than it is to build a giant trench with a highway in it.

As for I-30, the tear-down scenario just involves improvements to the frontage roads and rebuilt exit ramps. Trenching is the much larger and more complicated project with respect to I-30, as you have to build a highway underneath it and a whole new grade-switching highway interchange.

Yes, a totally rebuilt I-30 is included in the traffic model for the tear-down alternative, but it is also included in the traffic model for the below-grade alternative. It's an apples-to-apple comparison.

Perhaps running a scenario without an I-30 rebuild would show a greater congestion differential between tear-down and below-grade. Seems plausible. However, I would note that the I-30 rebuild is the city's top priority and is much more likely to come to fruition than any of these other projects, I-345 modifications included.

DO ALL THAT and then the overall traffic doesn't increase that much. Yes I agree with that 100%.


Sounds like we have a convert!

(Though I do want to point out that even if we do I-30 rebuild, Lowest Stemmons, Southern Gateway, Trinity Parkway, AND keep I-345 the way it is, congestion in the area is still projected to increase by 70% by 2040. The point to the findings is that I-345 tear-down won't increase it much *on top of that*. Mass transit, people!)

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Re: I-345

Postby Alex Rodriguez » 19 Oct 2017 09:57

tanzoak wrote:
As for I-30, the tear-down scenario just involves improvements to the frontage roads and rebuilt exit ramps. Trenching is the much larger and more complicated project with respect to I-30, as you have to build a highway underneath it and a whole new grade-switching highway interchange.

Yes, a totally rebuilt I-30 is included in the traffic model for the tear-down alternative, but it is also included in the traffic model for the below-grade alternative. It's an apples-to-apple comparison.


Well just have to disagree then. The report specifically says "Project Pegasus" which we just saw what that entailed for the Horseshoe portion. And I-30 rebuild is not part of the Below Grade option, I don't agree at all that the report says that.

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Re: I-345

Postby tanzoak » 19 Oct 2017 10:28

Alex Rodriguez wrote:Well just have to disagree then. The report specifically says "Project Pegasus" which we just saw what that entailed for the Horseshoe portion. And I-30 rebuild is not part of the Below Grade option, I don't agree at all that the report says that.


A-Rod, you're killing me. It specifically says that I-30 rebuild is part of the below-grade traffic analysis.

You're correct that I-30 rebuild is not part of *cost estimate* of the below-grade alternative. It is also not part of the cost estimate of the tear-down alternative.

I-30 rebuild is included, however, in the *traffic model* for both of them. Specifically, the 5-2-2-5 version of the rebuild, as indicated in the parentheses under "System with I-345 _______ Scenario" in this already-posted graphic.

Image

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Re: I-345

Postby tanzoak » 19 Oct 2017 10:36

I think you may be conflating the I-30 frontage and access enhancements included in the tear-down alternative with "I-30 rebuild," which is a separate project from I-345 and is included in the traffic analysis of both alternatives.

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Re: I-345

Postby tanzoak » 19 Oct 2017 10:38

Sorry if I'm being overly aggro. It's probably more difficult to parse than I'm giving credit, I just do this kind of analysis/help write these kinds of reports frequently.

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Re: I-345

Postby tanzoak » 19 Oct 2017 10:59

Like, that's fine if you just don't believe the results. It's certainly possible that tearing down I-345 will substantially increase congestion. Models aren't perfect.

But just know that this belief stands in opposition the most in-depth expert analysis to date. That analysis was properly conducted, and there's no obvious, easily-observable flaw to hang the traffic and/or cost nightmare belief onto.

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Re: I-345

Postby Alex Rodriguez » 19 Oct 2017 11:27

Look #1, a new study is already underway, so most of the conversation is moot. #2 this CityMap report is 430 pages, and covers 10+ different projects and then various scenarios for several of those 10+ projects. That graphic you keep posting is talking about I-30 East, I-30 Project Pegasus, I-345, I-35E, all jumbled into one graphic. I'm arguing the descriptions from 187, 191, 194. Anyway....

The way I've read this report is it only confirms the fact that you can't just tear down I-345, by itself, and be done. You are going to have to do a bunch of work just to make downtown traffic bearable. Tearing down I-345 removes 200K cars per day capacity. Period, end of story. You can add back some of that capacity by doing massive improvements to the rest of the system, I totally agree with that.

However, if you tunnel, you keep virtually all that capacity, plus can reclaim most of the land on top. That's a win. And down the line you can improve the system from there by doing Pegasus and all the rest. You are adding capacity starting from zero. Its all net improvement. Not starting from -200,000 and then adding capacity just to get back close to zero.

Thanks...good discussion.

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Re: I-345

Postby tamtagon » 19 Oct 2017 11:36

I not opposed to remove and replace, and I'm not opposed to renovate and repair.... as long as both re-establish a seamless flow of downtown's two streetgrids between the CBD and East Dallas.

The Maple-Routh-Good-Latimer-Chavez boulevard would become the CBD highway exit for most folks coming from the North and East, the superhighway loop-de-loo would is for those folks going between Central and I-30 who did not take Peak-Haskell.

or

I-345 is rebuilt with longer spans to eliminate virtually all impact on Downtown/East Dallas' two streetgrids, and the Maple-Routh-Good-Latimer-Chavez Boulevard still becomes the primary CBD access point.

The existing mad jumble of concrete columns all over the place, dead ends and wonky thru-ways have got to go.

I do kinda like the physical separation the highway creates, you know for sure, totally, when you're going between into Deep Ellum or the CBD.

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Re: I-345

Postby cowboyeagle05 » 19 Oct 2017 12:51

Alex Rodriguez wrote:Look #1, a new study is already underway, so most of the conversation is moot. #2 this CityMap report is 430 pages, and covers 10+ different projects and then various scenarios for several of those 10+ projects. That graphic you keep posting is talking about I-30 East, I-30 Project Pegasus, I-345, I-35E, all jumbled into one graphic. I'm arguing the descriptions from 187, 191, 194. Anyway....

The way I've read this report is it only confirms the fact that you can't just tear down I-345, by itself, and be done. You are going to have to do a bunch of work just to make downtown traffic bearable. Tearing down I-345 removes 200K cars per day capacity. Period, end of story. You can add back some of that capacity by doing massive improvements to the rest of the system, I totally agree with that.

However, if you tunnel, you keep virtually all that capacity, plus can reclaim most of the land on top. That's a win. And down the line you can improve the system from there by doing Pegasus and all the rest. You are adding capacity starting from zero. Its all net improvement. Not starting from -200,000 and then adding capacity just to get back close to zero.

Thanks...good discussion.


You don't reclaim all the land on top. The airspace over the trench will only allow certain kinds of development that won't endanger the freeway which basically means Klyde Warren part two. Having a park I admit is the not the worse thing but I would prefer more developable land for tax-generating residents/office workers and commercial retail/restaurants than another trench that does nothing for Dallas but enable more traffic headaches for suburbanites passing through.

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Re: I-345

Postby DPatel304 » 19 Oct 2017 12:53

cowboyeagle05 wrote:You don't reclaim all the land on top. The airspace over the trench will only allow certain kinds of development that won't endanger the freeway which basically means Klyde Warren part two. Having a park I admit is the not the worse thing but I would prefer more developable land for tax-generating residents/office workers and commercial retail/restaurants than another trench that does nothing for Dallas but enable more traffic headaches for suburbanites passing through.


Even if it is just another park, it'll drastically change the area immediately around the freeway.

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Re: I-345

Postby cowboyeagle05 » 19 Oct 2017 12:56

DPatel304 wrote:
cowboyeagle05 wrote:You don't reclaim all the land on top. The airspace over the trench will only allow certain kinds of development that won't endanger the freeway which basically means Klyde Warren part two. Having a park I admit is the not the worse thing but I would prefer more developable land for tax-generating residents/office workers and commercial retail/restaurants than another trench that does nothing for Dallas but enable more traffic headaches for suburbanites passing through.


Even if it is just another park, it'll drastically change the area immediately around the freeway.


Agreed but I prefer the tax generating revenue of a total reclaiming of the land over just another tax burden trophy park any day.

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Re: I-345

Postby Alex Rodriguez » 19 Oct 2017 13:16

I would rather they do a full tunnel anyway. Trench is okay but full tunnel like Big Dig or Alaska Way in Seattle is how I would prefer they do it. But due to cost, likely will end up being a trench. As long as they don't do something dumb like build frontage roads, with a Trench you can reclaim a bunch of the current land, but correct - not all. The new trench footprint and right of way will be much more narrow than the current I345 plus all the ramps, so you reclaim all that land, and then whatever deck park is built over the top.

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Re: I-345

Postby tanzoak » 19 Oct 2017 14:47

Alex Rodriguez wrote:Look #1, a new study is already underway, so most of the conversation is moot.

That graphic you keep posting is talking about I-30 East, I-30 Project Pegasus, I-345, I-35E, all jumbled into one graphic. I'm arguing the descriptions from 187, 191, 194. Anyway....

The way I've read this report is it only confirms the fact that you can't just tear down I-345, by itself, and be done. You are going to have to do a bunch of work just to make downtown traffic bearable. Tearing down I-345 removes 200K cars per day capacity. Period, end of story. You can add back some of that capacity by doing massive improvements to the rest of the system, I totally agree with that.

However, if you tunnel, you keep virtually all that capacity, plus can reclaim most of the land on top. That's a win. And down the line you can improve the system from there by doing Pegasus and all the rest. You are adding capacity starting from zero. Its all net improvement. Not starting from -200,000 and then adding capacity just to get back close to zero.

Thanks...good discussion.


Arrrgh. I've been talking about both. There are two things: cost estimates of the individual I-345 projects, and traffic estimates that include those individual projects + others.

1. The individual project of I-345 tear-down. This is described, and yes, it does involve components other than literally just a tear down, such as improvements to the I-30 frontage roads and reconstructing the Woodall Rogers interchange. That is all included in the cost estimate. I-30 rebuild is not. Pegasus Project != I-30 rebuild.

Even if it did, and I-30 rebuild was meant to be included in the tear-down alternative, that would just mean that the cost estimate for that alternative was off. However, the relative congestion estimates would be unchanged because I-30 rebuild is also included in below-grade.

Additionally, in the case where I-30 rebuild is included in the tear-down alternative but not the below-grade alternative and the traffic estimates are done only with the individual projects.. while the cost estimate for tear down would be higher, the traffic estimates would show that tear down alternative results in much lower congestion than below-grade alternative, assuming that I-30 rebuild actually improves congestion by more than just 1k/yr.

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Re: I-345

Postby Alex Rodriguez » 19 Oct 2017 15:20

I just found this, I-30 Project Pegasus estimate was $600 million dollars in 2015. It's the Canyon from I-30 to I-45. Again, $600 Million just to do the I-30 rebuild prerequisite for the Tear Down Scenario as described on page 191 of your report. $600 million estimate 2 years ago, by the time its actually done, it will be more like $700 Million. The Horseshoe officially came in at $800 million. So while its not $1B, the 100M-499M number obviously doesn't include this.

http://www.keepitmovingdallas.com/sites ... 0Paper.pdf

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Re: I-345

Postby tanzoak » 19 Oct 2017 15:44

Alex Rodriguez wrote:I just found this, I-30 Project Pegasus estimate was $600 million dollars in 2015. It's the Canyon from I-30 to I-45. Again, $600 Million just to do the I-30 rebuild prerequisite for the Tear Down Scenario as described on page 191 of your report. $600 million estimate 2 years ago, by the time its actually done, it will be more like $700 Million. The Horseshoe officially came in at $800 million. So while its not $1B, the 100M-499M number obviously doesn't include this.

http://www.keepitmovingdallas.com/sites ... 0Paper.pdf


What's your point? You're not responding to what I'm saying.

It's clear from all of the maps detailing the project and all of the detailed descriptions and the price estimate that I-30 rebuild is not included in tear down. You're focusing on one instance of the phrase Project Pegasus, which has other I-30 improvements as well, in addition to Lowest Stemmons. They were obviously referring to the non-rebuild components of PP with that phrase. Don't be obtuse.

Regardless, and more importantly, the inclusion (or not) of I-30 rebuild in tear-down alt does not lead to your conclusions about project assessment. If indeed I-30 rebuild is included in tear-down and not below-grade, then when the projects are considered in isolation tear-down would have a somewhat higher cost than below-grade, but it would also have *much* lower congestion than below-grade, as below-grade would no longer have that major congestion-relieving project included in its traffic analysis.

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Re: I-345

Postby tanzoak » 19 Oct 2017 15:49

The difference between tear-down + I-30 rebuild and below-grade + I-30 rebuild is only 700 hours. I don't know what's so difficult to grasp about that.

If you want to assign I-30 rebuild to tear-down, fine. But if you're then comparing it to below-grade sans I-30 rebuild, below-grade is going to have wayyyy worse traffic numbers.

You're trying to assign I-30 rebuild cost only to tear-down, while giving I-30 traffic benefit to both tear-down and below-grade. That's not how it works.

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Re: I-345

Postby Alex Rodriguez » 19 Oct 2017 16:12

The whole impetus for this discussion was your post way back when and supposition that tearing down I-345 has little to no impact on traffic numbers. You posted

Hours of delay in 2040:
Tear Down - 163.8k
Lower - 163.1k
Replace - 161.3k


I said post the link where you get this. You did. I read it. Page 191 describes the Tear Down Option, Page 194 describes the Trench Option.

To get to this 163.8K traffic number for Tear Down, the description on what has to happen to get 163.8K is right there on page 191. Middle of Page 191 for Tear Down, and I quote, "The changes to I-30 in the Canyon would include implementation of the improvements that were identified in Project Pegasus..." Plus a bunch of other major stuff. Go read it. Then read 194. To get to the Trench 163.1K number, read the description of what they do.

That's it. All the other stuff, the I-30 trench east of I-45, Lower Stemmons, etc etc, has no bearing on anything in regards to comparing the two options for I-345.


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