Dallas IH 345 study RFQ

[Bobby5280]

If complete removal of I-345 was going to be an option that issue should have been settled 15 years ago when the Horseshoe Project was still in its planning stages. The Horseshoe could have been designed to handle at least some of the traffic burden coming from I-45.

TX DOT appears to be promoting the buried freeway option and thankfully at least some city leaders in Dallas seem receptive to that as opposed to completely removing the freeway.

For I-345 to be completely removed from downtown Dallas and not cause major traffic increases on surface streets and other freeways I-45 would have to be removed clear down to I-20. They might as well tear out the US-175 freeway in South Dallas (and that new connecter under construction linking the C F Hawn Freeway with I-45). That funnels a bunch of traffic into downtown via I-45 too.

By the way, I've heard new urbanist types campaigning for the removal of I-30 from downtown Dallas as well, which is an even more ridiculous propositon. What's next? Get rid of I-35E as well? I don't know about anyone else, but there's no way in hell I would visit a giant city's downtown area if I had to drive through dozens of traffic lights to get there. I would only visit destinations in the suburbs. The funny thing is I pretty much do that already with trips down to the Dallas area.

As for pitching mass transit, the park and ride concept may work for commuters who work in the downtown area. It's not so practical an idea for tourists and other visitors. That might explain why the biggest tourist attractions in the DFW area are not in downtown Dallas.

I lived in New York City for 5 years. I rode the bus and subway there frequently. But it wasn't something I wanted to do. It was something I had to do. I knew plenty of people who flatly refused to ride the subway. They did so out of fear of crime (which was bad back then). They also hated the crushing crowds, nasty smells and other unpleasant features. It was as still is a status symbol to at least take a cab, drive or have a car service.

I'm not anti freeway, i'm anti this tiny elevated piece of crap.

I wouldn't exactly call that elevated freeway "tiny." It's pretty big, but it is ugly too.

[Stormwalker]

You come off as pretty anti freeway, not just because you oppose this one.

If the thousands of photos on this website I've taken since 2002 don't convince you otherwise maybe this analogy will:

I really like cars but I'm anti 1972 Ford Pinto. This particular freeway just sucks.

I think everyone agrees that I-345 as it currently exists is terrible, and not just because It's an eyesore.  The traffic flow is terrible.  Large scale reworking is needed.

Even so, making it a city street is not the answer.  Either an improved elevated freeway or a tunnel like Woodall Rogers is needed to meet the traffic flow requirements. 

Speaking as a resident of Dallas (proper, not suburb), I think that even if a new (likely insanely expensive) bypass of Dallas was built and all I-35E and I-45 traffic rerouted, the local traffic alone would still need an I-345 in some form

EDIT: corrected types (really should not use phone to post!)

[austrini]

These are the 2016 traffic counts by TxDOT



177,000 vehicles per day is a serious traffic volume. According to the map, this is the volume between all exits to Downtown Dallas, so it is through traffic. You can't just detour this traffic via I-35E or I-635. Apart from the required additional mainline capacity, it would also require significant reconstruction of the freeway-to-freeway interchanges, because a typical 1 or 2 lane connector is not designed to handle that kind of additional traffic.

I think they should put the freeway below grade with eight lanes and handle downtown-bound traffic via surface streets, where it can disperse across the grid. A freeway similar to the Woodall Rodgers, but with a longer deck, between 1 and 1.5 mile in length. This will be benificial to both mobility and the city for decades to come.

OK, let's say you have 177,000 vehicles per day. If they are passing through, they don't need to be in the center city. That's why Washington has a beltway, Atlanta has a perimeter, London has an orbital, and Dallas has 635, 161, or LOOP 12 (or lots of other freeways actually). How many does that get rid of?

Then you have people going into downtown. There no reason for anyone with a destination in downtown to need a freeway THROUGH downtown. How many does that get rid of?

Then you have people going from the northern parts of the city to the southern parts. In fact the only remaining people are going from one specific area of Dallas to another specific area of Dallas - because every other direction has a better route. In that instance the remaining motorists, of which there aren't that many, are welcome to use the 22 6-lane and 6 4-lane  arterial routes that serve those areas. Ta da.

[Stormwalker]

177,000 vehicles per day is a serious traffic volume. According to the map, this is the volume between all exits to Downtown Dallas, so it is through traffic. You can't just detour this traffic via I-35E or I-635. Apart from the required additional mainline capacity, it would also require significant reconstruction of the freeway-to-freeway interchanges, because a typical 1 or 2 lane connector is not designed to handle that kind of additional traffic.

I think they should put the freeway below grade with eight lanes and handle downtown-bound traffic via surface streets, where it can disperse across the grid. A freeway similar to the Woodall Rodgers, but with a longer deck, between 1 and 1.5 mile in length. This will be benificial to both mobility and the city for decades to come.

OK, let's say you have 177,000 vehicles per day. If they are passing through, they don't need to be in the center city. That's why Washington has a beltway, Atlanta has a perimeter, London has an orbital, and Dallas has 635, 161, or LOOP 12 (or lots of other freeways actually). How many does that get rid of?

Then you have people going into downtown. There no reason for anyone with a destination in downtown to need a freeway THROUGH downtown. How many does that get rid of?

Then you have people going from the northern parts of the city to the southern parts. In fact the only remaining people are going from one specific area of Dallas to another specific area of Dallas - because every other direction has a better route. In that instance the remaining motorists, of which there aren't that many, are welcome to use the 22 6-lane and 6 4-lane  arterial routes that serve those areas. Ta da.

That's nice in theory.  Personally, I think it would have been better if I-45 and I-35E had bypassed Dallas to begin with instead of going through the city center (we'd still need arterial freeways for local traffic, however).  In practice, it just doesn't fly, because...

1). 635 can't remotely handle that traffic.  It can't really handle the traffic it has now.  Expanding it to the size it would need to be to handle that much traffic is not at all feasible - the right-of-way issues in some areas (especially the northeast quarter) make it impossible.  You'd have to build a completely new outer loop - how much would that cost, and would the through traffic be willing to go that far out of the way to the east to begin with?

2). Loop 12 certainly can't handle it.  The west part of Loop 12 is the only segment which is a freeway; the rest of it is on city streets.  There's no really viable connector from I-35E to Loop 12 in the south, much less I-45... you'd have to divert traffic onto I-20 West and then to Spur 408, neither of which is ready for that load... nor is the freeway segment of Loop 12 itself, which already has congestion issues of its own.

3). What "lots of other freeways?".  Dallas' freeway and tollway system consists of...
a). Radial routes through the city center - the "spokes" in Dallas' wagon wheel layout:

• I-45 - Part of the main thing you're trying to divert traffic from.
• US 75- The other part of the main thing you're trying to divert traffic from.  Really needs to be designated as part of I-45 anyway.
• I-35E - The other thing you're trying to divert traffic from.
• I-30 -West-to-Northeast, also carries traffic into downtown, so it's part of your problem.
• US 80 See I-30.
• US 175 - Routes traffic onto I-45, so it's part of your problem as well.
• Dallas North Tollway - starts in downtown and goes north, therefore not usable for bypassing downtown.
• SH 183 (which I initially forgot), which branches off of I-35E north of downtown and heads northwest, not really relevant to bypassing downtown.
  

b). Circumferential routes - none of which provides a complete loop freeway

• SH Loop 12 - Previously addressed.
  
• I-635/I-20 (I still tend to think of this as all being 635, since when I grew up 20 still multiplexed with 30 into downtown) - Previously addressed.
• President George Bush Turnpike - Not even a half-circle at this point, from I-30 to I-30.  Certainly not of any use in relieving traffic from I-45 or I-35E, since you can't really get to it from south of downtown without going through downtown!

c). Connectors

• I-345 - 'nuff said.
• SH Spur 366 (Woodall Rogers Freeway) - connector on the north side of downtown, connects I-35E to US 75 and I-345.  As it exists entirely in the downtown area, not really relevant to the idea of diverting traffic away from downtown.  Also pretty congested already.
• SH Spur 408 - connects I-20 in the south to Loop 12.  Previously touched on when addressing Loop 12.

The "other freeways" you seem to think should be handling this traffic do not exist.  They would have to be built; while that's a great idea, and might be the best long-term solution for Dallas' traffic problems, where's the money going to come from?  And what about the people who live in the areas where those freeways would be built?  They wouldn't be any happier about that than Deep Ellum residents are about I-345.  Finally, what's going to happen during the time between tearing down I-345 and building the new freeways?  It'd make downtown a bigger traffic nightmare than it already is.

In the end, Dallas' freeway system is designed to route traffic through downtown.  Unless you first change that, removing I-345 would be nothing short of a disaster.

EDIT: Fixed wonky formatting, added SH 183 which I initially forgot.[/list]

[austrini]

What do you mean by can't handle - you mean you can't physically fit more cars on them or what? What are you basing that assertion on? What's the capacity that they'd have to bear that they can't handle? What part of the 345 AADT gets shifted to Loop 12, 635, 161, 360, PGBT? You mean its going to be stop and go traffic for 4 hours a day like it is now? so? 635 just can't handle it.

You can't bury it, there's a subway going in. I guess you could finagle it under or over the subway tunnel.

The TxDOT CityMap study http://dallascitymap.com/results.html#home doesn't say the others can't handle it.

I'll give you one thing, there is a dog park under 345 that's dry on rainy days like today and it's very nice to walk the dog down there.

[hotdogPi]

What do you mean by can't handle - you mean you can't physically fit more cars on them or what? What are you basing that assertion on? What's the capacity that they'd have to bear that they can't handle? What part of the 345 AADT gets shifted to Loop 12, 635, 161, 360, PGBT? You mean its going to be stop and go traffic for 4 hours a day like it is now? so? 635 just can't handle it.

You can't bury it, there's a subway going in. I guess you could finagle it under or over the subway tunnel.

The TxDOT CityMap study http://dallascitymap.com/results.html#home doesn't say the others can't handle it.

I'll give you one thing, there is a dog park under 345 that's dry on rainy days like today and it's very nice to walk the dog down there.

Yes. Roads do have a maximum capacity, usually around 2200 vehicles per hour per lane. And this number corresponds with traffic that is slightly congested but almost at free-flow speeds – adding any cars past this point decreases traffic flow.

[TXtoNJ]

Well, this thread went as expected.

austrini, I'm 100% with you on this one. 345 isn't needed. However, any sort of freeway removal has a tendency to rustle tribal jimmies.

[Stormwalker]

What do you mean by can't handle - you mean you can't physically fit more cars on them or what? What are you basing that assertion on? What's the capacity that they'd have to bear that they can't handle? What part of the 345 AADT gets shifted to Loop 12, 635, 161, 360, PGBT? You mean its going to be stop and go traffic for 4 hours a day like it is now? so? 635 just can't handle it.

You can't bury it, there's a subway going in. I guess you could finagle it under or over the subway tunnel.

The TxDOT CityMap study http://dallascitymap.com/results.html#home doesn't say the others can't handle it.

I'll give you one thing, there is a dog park under 345 that's dry on rainy days like today and it's very nice to walk the dog down there.

When you add more traffic to a highway which already has hours of stop-and-go traffic, those hours are extended, they don't just stay the same.

Expansion of I-635 to enable it to handle it's current and projected traffic loads is planned, but it is currently unfunded and likely to be very, very expensive, as the most likely solution involves burying lanes in a trench as there is nowhere else to put them; the ROW is very cramped.  Expanding it further to accommodate through traffic loads on top of that... I'm not sure that would even be possible. 

Putting I-345 in a cut-and-cover trench, as costly as it would be, is almost certainly less expensive than expanding 635 to act as a Dallas bypass for all through traffic would be!

As noted, in principle I agree that through traffic should not be routed through city centers.  Unfortnately, that's what Dallas' freeway system is currently built to do Removing 345 will not fix that.

You can't just remove a critical thoroughfare without providing that traffic another way to go.  If you want to remove 345, that's fine... fix the system so 345 is no longer needed, then get rid of it.  For now, It's essential.

[austrini]

Well, this thread went as expected.

austrini, I'm 100% with you on this one. 345 isn't needed. However, any sort of freeway removal has a tendency to rustle tribal jimmies.

Well, we can't inconvenience anyone from Plano. Heaven forbid they have to drive through Mesquite or Irving. How horrible would it be to be like Vancouver or Paris and not have freeways in the city center. Not even no freeways, just one less.

It's an interesting case study because there are thousands of local people who want 2.5 billion dollars in added property value and a quieter neighborhood, and a subway. Then you have armchair commentators from Oklahoma who are annoyed that it might take longer to get to the beach. The TxDot Citymap study referenced will explain more, and my inkling (that the existing study says) is that removing 345 isn't really that big of deal.

I love Star Trek. I'm a nerd. As a lover of Star Trek I have to admit that like 20% of Star Trek is mindbogglingly stupid. That's OK, I still love it. Same with roads. I don't want a freeway along the National Mall. I love the 635 express lanes.

[Plutonic Panda]

You come off as pretty anti freeway, not just because you oppose this one.

If the thousands of photos on this website I've taken since 2002 don't convince you otherwise maybe this analogy will:

I really like cars but I'm anti 1972 Ford Pinto. This particular freeway just sucks.

Okay but the words you use really seem to imply you feel a certain type of way regardless of what pictures you take. I hardly ever take pictures of freeways but I love freeways. So that doesn't really mean much.

But you're simply saying remove it because it sucks ans fuck the people in Plano, well there are so many other instances and freeways where that logic could be implied. Even more so, why should Central Expressway be anything more than 2 lanes each way? I mean fuck the people that live far out and use them! Think of how many housing units could be built where the expanded lanes are?! Why should the residents of Highland Park have to deal with a freeway tearing through their neighborhood because some people want to live in Frisco and commute to downtown? Why should the 635 exist because it creates such a big barrier to those living right by it? I can go on and on.

The case of this freeway being in a heavily urban area that should be made more walkable requires attention. But a removal option creates a problem while solving another(it helping walkability is quite debatable). How about solving two problems. The area needs to be more walkable and commuters are an important part of the city and need mobility. A tunnel best serves this purpose. Unless of course you think people living in the suburbs don't contribute anything to the metro.

[Plutonic Panda]

Well, this thread went as expected.

austrini, I'm 100% with you on this one. 345 isn't needed. However, any sort of freeway removal has a tendency to rustle tribal jimmies.

Well, we can't inconvenience anyone from Plano. Heaven forbid they have to drive through Mesquite or Irving.

So where is the line drawn with this logic then? Because you can say the same thing about tons of other freeways that commuters could go through x community if y freeway is taken out. Where does it stop? Just with the freeway next to you? Uptown can't use that logic?

[Stormwalker]

Well, this thread went as expected.

austrini, I'm 100% with you on this one. 345 isn't needed. However, any sort of freeway removal has a tendency to rustle tribal jimmies.

It's an interesting case study because there are thousands of local people who want 2.5 billion dollars in added property value and a quieter neighborhood, and a subway. Then you have armchair commentators from Oklahoma who are annoyed that it might take longer to get to the beach. The TxDot Citymap study referenced will explain more, and my inkling (that the existing study says) is that removing 345 isn't really that big of deal..

If TxDOT believed that, they wouldn't be promoting the (very, very expensive!) cut-and-cover idea.  Which, incidentally, provides all the benefits you listed above and also provides for traffic to get where it needs to go.

Also, your repeated characterization of everyone who disagrees with you as "armchair commentators from Oklahoma" undermines your argument.  I for one oppose the removal of I-345 vehemently, and I am a lifelong resident of the Dallas area, and a current resident of the City of Dallas.

For what it is worth, I favor the cut-and-cover approach, even though, the likely expense makes me cringe.

[Plutonic Panda]

Is a cut and cover approach even being considered? Maybe I misread the study, but it seems they are only proposing a below grade option with a cap in the middle. Not a full cut cover apart from the freeway cap.

[Bobby5280]

OK, let's say you have 177,000 vehicles per day. If they are passing through, they don't need to be in the center city. That's why Washington has a beltway, Atlanta has a perimeter, London has an orbital, and Dallas has 635, 161, or LOOP 12 (or lots of other freeways actually). How many does that get rid of?

Last time I checked Washington, DC still had I-66, I-395, I-295/695 going right into the center of the city. Add to that a number of parkways and expressways that come close to DC. Not everyone uses the Capitol Beltway. A shit-ton of traffic uses I-395.

As for Atlanta, same thing. I-20, I-75 and I-85 go right thru downtown. The combined I-75/I-85 roadway is 14 or 16 lanes across in some places.

As for London, it's very easy to understand why there's no freeways running right through the middle of the city. There's only a jillion old historical buildings that were crammed into the city center many hundreds of years old before the car was invented. But the city is completely covered with all kinds of streets. Cities in the United States aren't nearly that old. They weren't designed around horse drawn carriages and people on foot.

[sparker]

Is a cut and cover approach even being considered? Maybe I misread the study, but it seems they are only proposing a below grade option with a cap in the middle. Not a full cut cover apart from the freeway cap.

From what I understand, the below-grade option does specify a cap rather that a classic "cut & cover", which sui generis essentially means a deeper cut so that a significant earth layer (enough to support many types of foliage) can be placed atop the through facility's ceiling (similar to I-5 through Seattle).  A metal/concrete "cap", normally placed on joists above the freeway, can support traffic and possesses enough of a weight rating to handle anything that might show up in a city commons area (food trucks, for example) -- but not thick enough for root systems.  So what's on top might look more like a paved commons than a city park.  There will be some active ventilation required, of course; that'll need to be located somewhere along the edge of the cap itself.  Nevertheless, it would be an improvement over what's presently in place -- and actually much better than the boulevard approach, which would host much more in the way of pollution generators than a walkable city commons.     

[texaskdog]

Why not do what they keep doing in Austin?  Stripe it to one lane in each direction and the rest is for bikes...everyone here seems to think that will solve all traffic problems.

[Chris]

The vast majority of traffic on I-345 would likely originate within a 20-30 mile radius of Downtown Dallas, even though it may not necessarily have a destination in Downtown (at I-35E, 80% of traffic just passes through). There's no need to caricaturize it as a freeway solely for people from Houston to Oklahoma, that would be only a tiny fraction of those 177,000 vehicles per day.

While the cost of putting it below grade would likely be high, the cost of upgrading tens of miles of existing freeways and reconstructing many interchanges would be much greater.

[TXtoNJ]

The vast majority of traffic on I-345 would likely originate within a 20-30 mile radius of Downtown Dallas, even though it may not necessarily have a destination in Downtown (at I-35E, 80% of traffic just passes through). There's no need to caricaturize it as a freeway solely for people from Houston to Oklahoma, that would be only a tiny fraction of those 177,000 vehicles per day.

While the cost of putting it below grade would likely be high, the cost of upgrading tens of miles of existing freeways and reconstructing many interchanges would be much greater.

This is a situation where local, on-the-ground information contradicts what might be logical from how the system is laid out. From personal experience and that of others I know, everything austrini is saying is completely correct - you're simply not getting onto I-45 from North Dallas and Collin County  unless you're headed to Ennis or south. There is no significant local traffic in that corridor, and this is part of why it was so late to be built.

The cost of upgrading the existing freeways and interchanges may be greater, but they would also have much stronger network effects than sinking billions into 345.

[austrini]

Last time I checked Washington, DC still had I-66, I-395, I-295/695 going right into the center of the city. Add to that a number of parkways and expressways that come close to DC. Not everyone uses the Capitol Beltway. A shit-ton of traffic uses I-395.

As for Atlanta, same thing. I-20, I-75 and I-85 go right thru downtown. The combined I-75/I-85 roadway is 14 or 16 lanes across in some places.

People don't drive through central DC when they're driving from NYC to Miami. My point was that city centers don't need long haul traffic going through them. It doesn't economically benefit the city at all. That's why there are loops. That's the point of having them in the first place. If interstate traffic was meant to drive through city centers it makes the whole beltway system that Eisenhower envisioned a little bit pointless.

edit: or Roosevelt or whomever.

[austrini]

If TxDOT believed that, they wouldn't be promoting the (very, very expensive!) cut-and-cover idea.  Which, incidentally, provides all the benefits you listed above and also provides for traffic to get where it needs to go.

Also, your repeated characterization of everyone who disagrees with you as "armchair commentators from Oklahoma" undermines your argument.  I for one oppose the removal of I-345 vehemently, and I am a lifelong resident of the Dallas area, and a current resident of the City of Dallas.

For what it is worth, I favor the cut-and-cover approach, even though, the likely expense makes me cringe.

I am also a resident and live next to the stupid thing. Hell, I was born less than a mile from it. I said "armchair commentators from Oklahoma" one time. Not repeatedly and never once did I say "everyone who disagrees with me". Did I? It's not personal, it's just a throwback to an old planning ethos that is flawed. It has very, very, little pass-through local traffic (read the TxDot study, it's about 10%). You can look at it on a map and say, oh, it's a very important regional artery - it's not. No one is suggesting we remove Stemmons, Central, LBJ. Those are actually important and useful. Central is an example of how to do a freeway correctly, too. No one is suggesting to remove Woodall Rodgers. People are suggesting we remove this big structure that blocks two of the city's most important neighborhoods from each other, provides a great place to buy heroin at night, and provides people who just moved to Dallas white knuckle lane changing terror nightmares. If you live here, and you use it, where the hell are you going? It doesnt even go anywhere. You can use it to go to Ennis. You can use it to go to the impound lot when your car gets towed. You can use it to go to the big ass landfill. You can use it to go to the state fair for a couple weeks, but now everyone just takes the train because they rape you on parking.

I don't think burying or building below grade is an option, D2 is going in.

[Perfxion]

Texas highway system doesn't use the logic of the grid of the east coast. Like the power system, Texas is own its own. Houston and Dallas were dumb to build their highway systems to flow into their city centers and not on the edge or outside like other places. So getting rid of I-345, I-30, I-45, I-10, I-69 would be really dumb as it would crash the system. The whole spoke and wheel style doesn't help move traffic as the metro areas keep growing and nowhere to flow.

I-345 should be cut and covered, or a new highway built before I-20 to US75.

[Bobby5280]

People don't drive through central DC when they're driving from NYC to Miami. My point was that city centers don't need long haul traffic going through them. It doesn't economically benefit the city at all. That's why there are loops. That's the point of having them in the first place. If interstate traffic was meant to drive through city centers it makes the whole beltway system that Eisenhower envisioned a little bit pointless.

The fact remains there's still a shit load of people working in city centers like downtown Dallas. There's lot of other people visiting tourist spots, eating and socializing downtown. Most of those people do not live in or near downtown. There's your economic benefit for freeways into downtown right there.

This is why every major city in the United States has at least some sort of direct super highway access in its city center. Even in the early days of the Interstate highway system they were building freeways into the downtown areas. Most major cities still have large superhighways going through the central downtown areas. If you remove all the super highways in Dallas inside of the I-635 loop you'll see downtown Dallas fall into decay. No one will want to tolerate driving through dozens upon dozens of traffic lights just to get downtown. And taking mass transit doesn't live up to the Utopian image the New Urbanists are selling either.

I don't think burying or building below grade is an option, D2 is going in.

You do realize tunnels can be built on more than one level so they can cross over/under each other underground, right? There are examples of road & rail tunnels crossing each other underground in New York City, Boston and Washington DC.

Plus, the D2 thing is not a 100% done deal. They've settled on a preferred alternative alignment (which would cross under N Central at Swiss Ave). But the project is not all funded and not all the planning work is done either. Dallas is wanting to build a 26 mile Cotton Belt commuter rail line. They need to raise at least $2 billion for those projects, with a big chunk of it coming from federal sources. Good luck with that considering the current administration's ideology and the big tax cuts they just passed.

Texas highway system doesn't use the logic of the grid of the east coast. Like the power system, Texas is own its own. Houston and Dallas were dumb to build their highway systems to flow into their city centers and not on the edge or outside like other places. So getting rid of I-345, I-30, I-45, I-10, I-69 would be really dumb as it would crash the system. The whole spoke and wheel style doesn't help move traffic as the metro areas keep growing and nowhere to flow.

Please name these "other places" along the East Coast that have Interstate beltways but no super highways at all flowing into the city centers. What cities are you talking about specifically?

[austrini]

The fact remains there's still a shit load of people working in city centers like downtown Dallas. There's lot of other people visiting tourist spots, eating and socializing downtown. Most of those people do not live in or near downtown. There's your economic benefit for freeways into downtown right there.

Uhhh, if people are going to point B you don't need a freeway through point B.

[AlexandriaVA]

I see DC mentioned a bit so I figured I'd chime in.

Having a freeway cut through a central business district isn't terribly important to local economic health; neither DC nor NYC have freeways bisecting their prime central business districts (downtown for DC, midtown and lower Manhattan for NYC) and they're both doing fine, in terms of real estate and visitors. Driving on city streets isn't the end of the world.

[Bobby5280]

Uhhh, if people are going to point B you don't need a freeway through point B.

That's assuming everyone going to downtown Dallas is only going there from one direction. And that also assumes that everyone is going to the same destinations in Central Dallas.

Having a freeway cut through a central business district isn't terribly important to local economic health; neither DC nor NYC have freeways bisecting their prime central business districts (downtown for DC, midtown and lower Manhattan for NYC) and they're both doing fine, in terms of real estate and visitors. Driving on city streets isn't the end of the world.

Austrini (and now Perfxion) are tossing out this notion that cities that have their shit together only have a beltway and no super highway "spokes" going inside of that beltway. Both NYC and DC still have freeways reaching deep into the central business districts.

The West Side highway was turned into West Street South of 57th Street, but the FDR freeway on the East side of Manhattan still exists. The Battery Tunnel and Brooklyn Bridge both act as super highway spurs off the BQE into lower Manhattan. I-78 terminates in SoHo. 34th Street functions as a type of Breezewood for I-495. It's not like Manhattan or metro NYC is devoid of freeways inside the I-287 beltway.

If you remove the I-395, I-695, I-66, I-295/DC-295 and US-50 freeways from inside the Capitol Beltway it would seem like the end of the world to commuters all over the Greater DC area. That especially goes for I-395.