I-345

[DPatel304]

I haven't heard any updates about I-345 in a while. I used to be in the 'tear it down' camp, but now I'm pretty on board with keeping it.

It would be nice if it were possible to 'skinny' it up a little bit, sell some of the excess land to developers, and make the area underneath the highway much more pedestrian friendly (it's not half bad at the moment, honestly).

[TNWE]

I haven't heard any updates about I-345 in a while. I used to be in the 'tear it down' camp, but now I'm pretty on board with keeping it.

It would be nice if it were possible to 'skinny' it up a little bit, sell some of the excess land to developers, and make the area underneath the highway much more pedestrian friendly (it's not half bad at the moment, honestly).

Agreed - Eliminating the Elm/Main/Commerce connectors to I-30 and the "fly-arounds" that were built to alleviate the weaving needed for non-local traffic connecting between I-30 and I-345 would free up a lot of space. They could basically route all Downtown local traffic to/from I-30 and points south over the North/South arterials (Griffin/Akard/Ervay/Harwood/Cesar Chavez), rather than everyone trying to take Elm/Commerce to 345 to 30.

[Parker Road]

I'll echo that the main issue is that it's just too damn wide. TxDOT building roads as obnoxiously as possible is nothing new, but I-345 stands out through its blatant disregard for the street grid in the historically minority neighborhoods it cuts through. It forces over 2 blocks of nothingness along Elm/Main/Commerce sidewalks, and attempting to cross under it at any other point is even worse. Saying the crossing is "not that bad" is being generous.

The freeway does have a stronger "keep it" argument than others in question across the country because it isn't just a stub-end, it connects I-45 with the rest of the city, and it helps poorer residents in South Dallas commute to jobs to the North. Such is reality in an extremely sprawling area like DFW. The question is, do we need to continue to feed this sprawl or will we mitigate it? A 60-foot wide exitless viaduct with 11-foot lanes is a reasonable stopgap because such a reduction won't induce demand and improves the pedestrian environment. But I'd hate to see exorbitant money spent on burying/tunneling the same amount of lanes — I'd rather see the money spent elsewhere on things that strengthen transportation and development within the city center rather than encouraging even more travel away from it.

[quixomniac]

The freeway does have a stronger "keep it" argument than others in question across the country because it isn't just a stub-end, it connects I-45 with the rest of the city, and it helps poorer residents in South Dallas commute to jobs to the North. Such is reality in an extremely sprawling area like DFW. The question is, do we need to continue to feed this sprawl or will we mitigate it? A 60-foot wide exitless viaduct with 11-foot lanes is a reasonable stopgap because such a reduction won't induce demand and improves the pedestrian environment. But I'd hate to see exorbitant money spent on burying/tunneling the same amount of lanes — I'd rather see the money spent elsewhere on things that strengthen transportation and development within the city center rather than encouraging even more travel away from it.

I agree with the stopgap, for the South Dallas reasoning and pedestrian benefits. But also because I just dont see this city with all its bickering taking on such a huge endeavor and not messing it up. Still havent done anything with Trinity river, or D2. Whatever the solution, it needs to happen within the next 5 years or it will hamstring the momentum going between Deep ellum and the East Quarter.

[Tivo_Kenevil]

I'd rather trench and cover i-35 than 345

[dallaz]

I would love to see Dallas do this.

It maybe more expensive...but it’s a better alternative IMO. I’d even be down for a cut and cover...

https://youtu.be/zUvF0nDwTo4
https://youtu.be/LBfvEb0HbYg

[Hannibal Lecter]

^ $3.3 billion and ten years to complete.

[electricron]

Seattle's Alaska Way Viaduct was about to fall down, was a hazard on the last earthquake, and would probably self demolish itself with the next earthquake.

I-345 in comparison is in much better shape, is not in an earthquake zone, is not about to self demolish itself with the next tornado, and does not block the Gulf of Mexico views from downtown Dallas skyscrapers like the the Alaska Way Viaduct blocked views of Puget Sound.

Even so, while tearing down the Alaska Way Viaduct, Seattle did more than just build a tunnel underground, they also rebuilt Alaska Way at grade level too. There is just as much traffic now at grade and below grade along Alaska Way as there was before on the viaduct. They did not reroute traffic, they just changed how the traffic moved through the same locale.

Those suggesting tearing down I-345 have not made proposals on how to handle the same amount of traffic through the same locale; both local traffic into and out of downtown, and long distance traffic that wishes to bypass downtown. Instead, they have made proposals that would create massive traffic jams and gridlock in every compass points around downtown.

[Tucy]

^ TRUTH

[Hannibal Lecter]

^ Amen.

[cowboyeagle05]

Umm there have been proposals made how to handle the traffic but the disagreement is on how realistic those solutions are. To very over simplify the two camps one side says Traffic will detour and dissipate the other says that's ridiculous and that poor people will lose their jobs. Its easy to say the other side offers no solutions when you refuse to accept the other sides solutions because it doesn't fit your expectations.

[Hannibal Lecter]

What solutions have the tear down proponents offered other than "everything will just work out"?

[dallaz]

Initially, I was for the teardown of 345. Now I believe, a tunnel or something below grade would be a healthy compromise between both sides. Yes, it’s more expensive. But it’s also gives more opportunities to restitch some of the street grid. 345 may not sit by a large body of water or really anything geographically noteworthy, but I do believe the area would benefit from a below grade 345. Mainly, due to where it’s located. (Now, if 345 was nowhere near the core of Dallas...I would not be for a nontraditional option) I could be totally wrong, but I do believe it is something that should be considered.

[tamtagon]

I still don't mind the physical separation that comes with an overpass.

[electricron]

Initially, I was for the teardown of 345. Now I believe, a tunnel or something below grade would be a healthy compromise between both sides. Yes, it’s more expensive. But it’s also gives more opportunities to restitch some of the street grid. 345 may not sit by a large body of water or really anything geographically noteworthy, but I do believe the area would benefit from a below grade 345. Mainly, due to where it’s located. (Now, if 345 was nowhere near the core of Dallas...I would not be for a nontraditional option) I could be totally wrong, but I do believe it is something that should be considered.

So what would you do with I-30?
I just wanted to remind people that I-30 is already 25 feet below grade in an open ditch. All the city streets crossing above it are at grade level. For I-345 to tunnel under I-30, it would have to be at least 50 feet below grade - if not deeper. How would you then make ramps, especially for the left turners, for the i-30 to i-345 intersection? Under I-345 another 25 feet, or would you prefer lowering I-345 the additional 25 feet. Now it is at least 75 feet below grade.
Has anyone actually taken the time to realize how smart the highway engineers were back in the 1960s when they designed this intersection?
They were not fools!

Then consider this, DART’s light rail lines under Central Expressway is however deep the new tunneled i-345 would have to be under i-30. Then imagine having tunneled on and off ramps for the new intersection with I-30 at its existing grade. The at grade level would have the new avenue for local traffic. Would it have an intersection with on and off ramps to I-30? It is going to get messy really quickly. Guess what, that mess was solved in the 1960s when they designed the existing i-345 viaducts and its on and off ramps. It basically has worked successfully for 50 years. Why fix what is not broken? I suggest keep repairing and refurbishing it to last another 50 years, or until it fails to do the job adequately, like the Alaska Way Viaduct in Seattle failed.

[Tivo_Kenevil]

The on ramps for i345 are horrible at street level; i wouldn't give engineers that much credit... I345 wouldnt be so bad if it was just an over pass. But it's not...

[Tnexster]

I still don't mind the physical separation that comes with an overpass.

Ditto

[northsouth]

An overpass has the advantage that the land underneath is by default usable (if gloomy), unlike a trench where the deck has to be added. I think a reduced overpass that is just the through lanes with no exits is viable, maybe stacked double-decker style to minimize footprint.

[Tivo_Kenevil]

An overpass has the advantage that the land underneath is by default usable (if gloomy), unlike a trench where the deck has to be added. I think a reduced overpass that is just the through lanes with no exits is viable, maybe stacked double-decker style to minimize footprint.

That modified footprint was one of the options presented in the City Map studies of I recall correctly

[Parker Road]

That modified footprint was one of the options presented in the City Map studies of I recall correctly (image)

Oh man, the empty median in that image is still huge. If they go for the 4-lane elevated option they need to make it one narrow viaduct with a jersey barrier to preserve space. That means the Good-Latimer exit needs to be reconfigured or removed — but that area is horribly designed by 2020 standards anyway.

[TNWE]

That modified footprint was one of the options presented in the City Map studies of I recall correctly (image)

Oh man, the empty median in that image is still huge. If they go for the 4-lane elevated option they need to make it one narrow viaduct with a jersey barrier to preserve space. That means the Good-Latimer exit needs to be reconfigured or removed — but that area is horribly designed by 2020 standards anyway.

This is where I chime in to say Left Exits are Good, Actually. Yes, I know that the rules of the road say that the leftmost lane is for passing, and that highway design guidance has called for entrance/exit ramps on the right for decades, but when we're looking at urban freeways, all those rules need to be thrown out. Onramps should be on one side, and offramps on the other, with signage and a "point of no return" well away from the actual exit (so you don't have people using highways to skip traffic lights, recklessly cut across multiple lanes, or weave in and out of exit-only lanes in an attempt to beat traffic).

In the case of the Good-Latimer exit, there's zero reason someone would need to go from Woodall Rodgers -> 345 -> Good Latimer (they can exit Olive, then use surface streets to Routh), so moving that exit to the right side introduces another point of conflict as traffic from southbound 75 needs to weave with traffic entering from the access roads and 366. As it is, southbound 75 traffic knows as far back as Lemmon that they need to be in the Leftmost lane for the Good-Latimer exit, and ideally any 345 redesign would make Ross a left exit as well.

[Hannibal Lecter]

So you want to route traffic going from Woodall Rodgers to East Dallas and Deep Ellum along a winding path of downtown streets through downtown and the Arts District? You really want to dump all that thru traffic onto downtown streets?

Actually, I've taken that route more than a few times. And it sucks. Of the four main routes from southbound I-35E to Deep Ellum (I-35E to Commerce, I-35E to I-30 frontage to Cesar Chavez to Commerce, I-35E to Woodall Rodgers to I-45 to I-30 to Second Avenue) it's one of the worst. Surprisingly, outside of the heart of rush hour the Second Avenue route is usually the best.

My concept:

- Add a barrier to block southbound traffic from the Live Oak exit. They can take the left exit. This removes a lot of weaving at the Woodall Rodgers merger.

- Continue to allow Woodall Rodgers traffic to exit at Live Oak, but straighten the ramp to a standard T-intersection at Live Oak. This frees up the land, and makes for an easy left-hand turn onto Live Oak for Woodall Rodgers traffic going to East Dallas or Deep Ellum.

- Re-stripe the southbound NCX exit to downtown/Good-Latimer to allow the second inside lane to optionally exit or continue onto I-345. No new pavement needed; just re-stripe it. This discourages the asses who stay in the left lane to the last second, then block traffic waiting to cut in to the right, plus makes it easier on the surprising number of people who enter the freeway southbound from Haskell then have to merge all the way over to the left lane to get to the G-L exit.

[TNWE]

So you want to route traffic going from Woodall Rodgers to East Dallas and Deep Ellum along a winding path of downtown streets through downtown and the Arts District? You really want to dump all that thru traffic onto downtown streets?

Actually, I've taken that route more than a few times. And it sucks. Of the four main routes from southbound I-35E to Deep Ellum (I-35E to Commerce, I-35E to I-30 frontage to Cesar Chavez to Commerce, I-35E to Woodall Rodgers to I-45 to I-30 to Second Avenue) it's one of the worst. Surprisingly, outside of the heart of rush hour the Second Avenue route is usually the best.

The Olive off-ramp puts drivers at the Woodall Rodgers NB frontage, and from there it's two right turns to get on Routh towards Deep Ellum. The route around using I-35E-> I-30 is another option, which is generally more free-flowing than Woodall and relieves pressure on the 35E to Woodall ramps that frequently back up onto the main lanes.

If someone is trying to get from Uptown/West End to Deep Ellum, there's just no reason to hop on the freeway, but so long as there are possible routes, GPS apps will tell people to get on the freeway for a very short trip to save a minute or two, at the expense of making congestion worse for everyone else on the road.

I'm definitely not reflexively anti-freeway, but they should be designed in a way that discourages ultra-short trips.