I-55 Bridge in Memphis

[triplemultiplex]

I believe the tunnel discussion is about a third Mississippi crossing, not reviving the rightfully dead Overton Park thing.

[edwaleni]

There are tunnels under SF Bay.

The Transbay Tube was constructed in sections on land which were then floated out to the right location, submerged into a prepared trench, and then cushioned/fastened to the bottom with sand and gravel.

Constructing this way, and by avoiding bedrock, is thought to cushion the tunnel in such a way as to reduce the chance of failure in an earthquake.

I suppose that something equivalent could be done in Memphis, by cutting a trench, building the highway in the trench, and then covering/cushioning structure, but such a construction tactic would have many of the same park-disruption problems that killed the original I-40 ROW, plus the added disruption to all the houses that have since been constructed in the former right of way.   (I haven't paid attention to where things stand with the last un-redeveloped plot of the ROW.  Last I heard, neighborhood folks were trying to fix a problem of having no nearby parks, while developers were chomping at the bit at the prospect of being able to build in a part of town seen as up-and-coming.)

The only way you'd get I-40 tunneled under Memphis is by boring through the loess.   It'd be easy to bore the tunnels; it'd be far more difficult to bore the tunnels in such a way as to survive various potential causes of collapse.  (Although, in fairness, Google tells me that the Chinese have had some success...and a few failures...in this regard.)

I still don't see that happening to save 3 miles in a city that has been pursuing road diets, in a state that tends to be miserly when it comes to transportation projects in that part of the state.

Not I-40.  I was thinking I-55 using one on the recommended crossings posted earlier. One that completely eliminates crossing in the downtown.

While a direct tunnel is preferred usually due to costs, I am thinking of a NW/SE tunnel of I-55 that goes under on the Arkansas side either east of Bridgeport Road and come back out on the TN side either at McLemore, or a longer one with its entry at Bridgeport Road, but directed further SSE with a ventilation section on Presidents Island, going under MLK Park and coming up at Riverport Road.

The longer one becomes a sort of west bypass of downtown Memphis but retains the M-A bridge, the limited access to downtown Memphis, and takes all the pass through trucks off the M-A and the 1 lane circle ramp to go/from the south.

[wdcrft63]

Has the Brent Spence solution been proposed here?
In Cincinnati the existing 8-lane bridge will be relieved by building a new 10-lane bridge to carry the through traffic on I-71/75. The existing bridge will be reduced to 6 lanes with shoulders and limited to local traffic.
The Memphis version would be a new bridge somewhere to the south to carry the I-55 traffic with the old bridge limited to local traffic in and out of the city.

[MikeTheActuary]

I believe the tunnel discussion is about a third Mississippi crossing, not reviving the rightfully dead Overton Park thing.

I missed that or I'm getting threads messed up.  Mea culpa.

[Henry]

Has the Brent Spence solution been proposed here?
In Cincinnati the existing 8-lane bridge will be relieved by building a new 10-lane bridge to carry the through traffic on I-71/75. The existing bridge will be reduced to 6 lanes with shoulders and limited to local traffic.
The Memphis version would be a new bridge somewhere to the south to carry the I-55 traffic with the old bridge limited to local traffic in and out of the city.

I don't see what Cincinnati has to do with this, and they're probably not thinking about it right now.

[bwana39]

Has the Brent Spence solution been proposed here?
In Cincinnati the existing 8-lane bridge will be relieved by building a new 10-lane bridge to carry the through traffic on I-71/75. The existing bridge will be reduced to 6 lanes with shoulders and limited to local traffic.
The Memphis version would be a new bridge somewhere to the south to carry the I-55 traffic with the old bridge limited to local traffic in and out of the city.

I don't see what Cincinnati has to do with this, and they're probably not thinking about it right now.

I think the point is to build a new bridge to connect to I-55 south of the French Fort and repurpose The M&A for local traffic. There has been hundreds of comments discussing that possibility. It even SEEMS to make better sense than what they currently have on the table.

[civilengineeringnerd]

Has the Brent Spence solution been proposed here?
In Cincinnati the existing 8-lane bridge will be relieved by building a new 10-lane bridge to carry the through traffic on I-71/75. The existing bridge will be reduced to 6 lanes with shoulders and limited to local traffic.
The Memphis version would be a new bridge somewhere to the south to carry the I-55 traffic with the old bridge limited to local traffic in and out of the city.

I don't see what Cincinnati has to do with this, and they're probably not thinking about it right now.

I think the point is to build a new bridge to connect to I-55 south of the French Fort and repurpose The M&A for local traffic. There has been hundreds of comments discussing that possibility. It even SEEMS to make better sense than what they currently have on the table.

to be fair, they do need a new crossing sometime soon, something 10-laned thats basically cable stayed and a massive widening project east into town, away from downtown, and west around west memphis.
the cable stayed bridge would be much better at resisting earthquakes and tornadoes if done right, and the new crossing  would have piles going hundreds of feet in the ground to better withstand liquefaction that would be caused by the mississippi.
and it would obviously need to be tolled. now the city of memphis can basically add whatever they want to the bridge, including billboards, variable message signage, and whatever else they want, including a fancy new sign that showcases memphis' history and culture.
building such a bridge could also in theory jumpstart programs needed to get memphis from a crime ridden, and corrupt city, to basically something a bit better than they got currently and could help bring much needed economic jobs to the area.

[MikieTimT]

Has the Brent Spence solution been proposed here?
In Cincinnati the existing 8-lane bridge will be relieved by building a new 10-lane bridge to carry the through traffic on I-71/75. The existing bridge will be reduced to 6 lanes with shoulders and limited to local traffic.
The Memphis version would be a new bridge somewhere to the south to carry the I-55 traffic with the old bridge limited to local traffic in and out of the city.

I don't see what Cincinnati has to do with this, and they're probably not thinking about it right now.

I think the point is to build a new bridge to connect to I-55 south of the French Fort and repurpose The M&A for local traffic. There has been hundreds of comments discussing that possibility. It even SEEMS to make better sense than what they currently have on the table.

to be fair, they do need a new crossing sometime soon, something 10-laned thats basically cable stayed and a massive widening project east into town, away from downtown, and west around west memphis.
the cable stayed bridge would be much better at resisting earthquakes and tornadoes if done right, and the new crossing  would have piles going hundreds of feet in the ground to better withstand liquefaction that would be caused by the mississippi.
and it would obviously need to be tolled. now the city of memphis can basically add whatever they want to the bridge, including billboards, variable message signage, and whatever else they want, including a fancy new sign that showcases memphis' history and culture.
building such a bridge could also in theory jumpstart programs needed to get memphis from a crime ridden, and corrupt city, to basically something a bit better than they got currently and could help bring much needed economic jobs to the area.

I would certainly pay a reasonable toll (up to $8) to completely bypass W. Memphis/Memphis to the south and connect to I-269/I-22.  It's that segment alone that incentivized me to take I-530/US-65 to I-20/US-49 to the Gulf Coast from NWA for beach trips every 2-3 years.

A bridge that bypasses Memphis probably doesn't do much to jump start tourism or urban renewal, however, so it'll take tolling or federal funding before it's likely.

[bwana39]

https://www.fox13memphis.com/news/i-55-bridge-closing-for-two-weeks-tdot-says/article_174c31cc-da42-11ee-a227-97680dc7e7d8.html

2-week scheduled closure of M&A starting tonight (Sunday 3/10/24)

https://wreg.com/news/local/i-55-bridge-closed-for-construction/

[Rothman]

"M&A" is a thing?

[MikieTimT]

"M&A" is a thing?

Oh yes.  Even before I-55 was a thing since the bridge predates the Interstate Highway System.  Memphis & Arkansas is what it stands for.

Just hoping we don't have another group of Palestine protestors on the I-40 bridge shutting down all interstate traffic again.

[bwana39]

https://www.localmemphis.com/article/traffic/i-55-memphis-bridge-opens-after-two-week-closure-construction-work-nears-end/522-21d29446-940b-4188-bf0e-1cd30a7a3442

Bridge reopened Sunday on schedule

[Great Lakes Roads]

I-55 Mississippi River Bridge replacement project (or as TDOT is calling it, "The America's River Crossing").

All options are in the cable-stayed bridge design, but it's on the number of spans and towers.

1. Two towers with four spans
2. Three towers with four spans
3. Two towers with three spans

The new bridge will have four 12-foot travel lanes with two 12-foot auxiliary lanes and 12-foot shoulders on both sides.

[Plutonic Panda]

Good deal! I watched the video and there are renderings in it. Your wording did confuse me a bit about the number of travel lanes added. It looks the bridge will have 3 lanes each way with two being GP lanes and one being an auxiliary lane. I'm guessing the third auxiliary lane will exit at Crump BLVD.

[wriddle082]

Good deal! I watched the video and there are renderings in it. Your wording did confuse me a bit about the number of travel lanes added. It looks the bridge will have 3 lanes each way with two being GP lanes and one being an auxiliary lane. I'm guessing the third auxiliary lane will exit at Crump BLVD.

Yes I'm assuming that's the case.  Extending the third lane further south would be very messy, since 55 run in a concrete canyon for a couple of miles.  And Arkansas likely won't extend that third lane much past the first exit, since ultimately there is a duplex with 40 up ahead.

[vdeane]

And Arkansas likely won't extend that third lane much past the first exit, since ultimately there is a duplex with 40 up ahead.

Exit 3B would seem to be a nice place to end it, since that's where US 70 merges in with the West Memphis traffic.

[wriddle082]

And Arkansas likely won't extend that third lane much past the first exit, since ultimately there is a duplex with 40 up ahead.

Exit 3B would seem to be a nice place to end it, since that's where US 70 merges in with the West Memphis traffic.

Yeah that might be a good spot.  There are some issues with the bridges over the swamps between that point and the river, so this might be an excuse for ArDOT to rebuild those bridges.

[civilengineeringnerd]

And Arkansas likely won't extend that third lane much past the first exit, since ultimately there is a duplex with 40 up ahead.

Exit 3B would seem to be a nice place to end it, since that's where US 70 merges in with the West Memphis traffic.

Yeah that might be a good spot.  There are some issues with the bridges over the swamps between that point and the river, so this might be an excuse for ArDOT to rebuild those bridges.

the more important thing is earthquake resiliency. i watched a video simulation on a new madrid quake, and did some digging on what the earthquake terms would mean.
basically if the big one hit today, nothing would be left of memphis. when i say nothing, i mean absolutely nothing. in earthquakes, the severity of damage is measured in intensity from I to XII. in the simulation on earthquakesim youtube channel, memphis was hit with a XI intensity. while there was some towers left, it did not account for extreme liquefaction that would occur with such a intense earthquake so the damage would look more like XII or higher.
the bridge would give the national guard of both states and even FEMA some redundency and would allow for emergency transportation of national guard troops, army corps transport of critical supplies, and USGS and FEMA damage servey teams without needing a helicopter ride.
and with extreme liquefaction i doubt the I-40 bridge span would survive either, especially since there was that joint that had to be replaced last year.
even if the cost was over 2B US dollars it would be well worth it for the region in terms of securing a reliable connector route.
in addition, in some comments that was said about the bay bridge span and loma preieta earthquake of 1989, a 7.7 on the north american shelf would make loma look like childs play, since the P and S waves would travel much further without doing much in weakening. there was estimates from FEMA themselves suggesting that a earthquake in the new madrid seismic zone would reach 300 Billion dollars in direct economic losses. that was done in 08. imagine with the growth in the region just how much more would be affected. 400B? 600B?
so 2B dollars on a replacement bridge span would be peanuts compared to the elephant that is a earthquake from new madrid. and to the comments about french fort and the black population there, mother earth does not answer to mans concerns of their houses and property, and mother earth does not discriminate either. even if there was pushback, the replacement should be a urgency that supersedes the plight of man, because a new bridge to replace the current one for I-55 would be much better for the entire region, because the nearest bridges that would probably be in much better shape is further south into Louisiana and southern Arkansas, basically along US Route 278 between lake village AR and greenville MS, and the I-72 bridge that crosses the mississippi river at hannabal MO.
a very LONG detour that would be problematic with getting critical Aid and Medical Supplies to the affected areas post big one, when in a few weeks, both DOTs could get the Major Interstate Roads working again with temporarily roads like what florida did with the keys along US 1 and what PennDOT did with I-95 with a replacement Bridge span of I-55 that is earthquake resistant.
it may sound heartless of me to say such a thing, but the I-55 bridge and a 3rd bridge span, perhaps with I-269, should be built with urgency and expediency, the time for, pardon my french, jerking off is over, the time for preparedness and redundancy is now. in the meantime, if any group in memphis has a problem with a bridge replacement, let the popcorn pop and the soda flow for the biggest political show the world has ever bore witness to.   

[The Ghostbuster]

How many residents of Memphis are aware that the New Madrid Seismic Zone exists? The entire city (and the surrounding area within the seismic zone) should be earthquake-hardened (especially the roads and river bridges, and yes, even the buildings). An earthquake can strike anywhere at any time.

[lordsutch]

How many residents of Memphis are aware that the New Madrid Seismic Zone exists? The entire city (and the surrounding area within the seismic zone) should be earthquake-hardened (especially the roads and river bridges, and yes, even the buildings). An earthquake can strike anywhere at any time.

I think it's pretty common knowledge in the region, and something that TDOT and neighboring transportation agencies have prepared a lot for, but it's probably not as close to the top of the average person's mind as it is in places that have more frequent earthquakes like SF and LA; in the near-decade I lived in Memphis, St. Louis, and thereabouts, I don't remember a single noticeable earthquake, although perhaps people closer to New Madrid itself feel them more frequently. The University of Memphis has a fairly well-known seismology center and it does get reported on quite a lot in the media. The 1812 earthquake is a staple of local history (as much as the Civil War and the assassination of MLK) so anyone who grew up in the area would know about it.

[bwana39]

If the fault hits that big a bridge across the Mississippi River is going to be the least of their worries. It honestly might result in a bridge still standing with no approaches or connecting roads being passable.

[bwana39]

I think it's pretty common knowledge in the region, and something that TDOT and neighboring transportation agencies have prepared a lot for, but it's probably not as close to the top of the average person's mind as it is in places that have more frequent earthquakes like SF and LA; in the near-decade I lived in Memphis, St. Louis, and thereabouts, I don't remember a single noticeable earthquake, although perhaps people closer to New Madrid itself feel them more frequently. The University of Memphis has a fairly well-known seismology center and it does get reported on quite a lot in the media. The 1812 earthquake is a staple of local history (as much as the Civil War and the assassination of MLK) so anyone who grew up in the area would know about it.

The New Madrid is not a frequently quaking fault. It tends to move suddenly and violently with several decades between any significant activity.