AARoads Forum

Regional Boards => Southeast => Topic started by: Chrysler375Freeway on November 04, 2021, 11:25:55 PM

Title: Nashville Infrastructure Upgrade
Post by: Chrysler375Freeway on November 04, 2021, 11:25:55 PM
Does anyone here (other than me) think it's time to upgrade Nashville's infrastructure considering it's getting crowded and traffic is increasing? And how should it be upgraded? What can be done to upgrade the infrastructure of the Nashville area as a whole to handle the population increases?
Title: Re: Nashville Infrastructure Upgrade
Post by: froggie on November 05, 2021, 12:00:42 AM
https://www.aaroads.com/forum/index.php?topic=13237.0
Title: Re: Nashville Infrastructure Upgrade
Post by: tolbs17 on November 05, 2021, 12:10:49 AM
I see a lock coming...
Title: Re: Nashville Infrastructure Upgrade
Post by: Chrysler375Freeway on November 05, 2021, 12:20:44 AM
I currently do not see any new posts on the topic in the link after clicking it. I even tried refreshing the browser and going to the latest page.
Title: Re: Nashville Infrastructure Upgrade
Post by: vdeane on November 05, 2021, 12:38:21 PM
Quote from: Chrysler375Freeway on November 05, 2021, 12:20:44 AM
I currently do not see any new posts on the topic in the link after clicking it. I even tried refreshing the browser and going to the latest page.
He's telling you that there's no need to spam the forum with a separate thread.
Title: Re: Nashville Infrastructure Upgrade
Post by: civilengineeringnerd on November 13, 2022, 11:49:27 PM
Quote from: Chrysler375Freeway on November 04, 2021, 11:25:55 PM
Does anyone here (other than me) think it's time to upgrade Nashville's infrastructure considering it's getting crowded and traffic is increasing? And how should it be upgraded? What can be done to upgrade the infrastructure of the Nashville area as a whole to handle the population increases?
personally, it needs to be upgraded as follows:
interstates 40, 24 and 65 need to have separated collector/disturber (or express and local lanes).
express lanes can be 4 lanes while local lanes can be 6. complete I-440 around to the other side of I-40 and have a I-265 to connect up from I-65 to the southwest to I-24 to the northwest (near clarksville)
force all thru traffic to funnel into I-840, I-440 and I-265
then have each of those, as well as briley parkway to be express and local laned as well.
with 4 express and 3 local lanes.
upgrade the downtown loop with removal of exits, to a express and local lane setup, 10 express and 12 local with bare minimum of 3 laned exit/entrance ramps. 1-2 of the local lanes can be exit ramps.
reconfigure all interchanges to match the widening.
if the city of nashville wants, they can have a middle bus/tram/metro corridor down the middle of each one.   :bigass: :-P
Title: Re: Nashville Infrastructure Upgrade
Post by: I-55 on November 14, 2022, 01:09:48 AM
Quote from: civilengineeringnerd on November 13, 2022, 11:49:27 PM
Quote from: Chrysler375Freeway on November 04, 2021, 11:25:55 PM
Does anyone here (other than me) think it's time to upgrade Nashville's infrastructure considering it's getting crowded and traffic is increasing? And how should it be upgraded? What can be done to upgrade the infrastructure of the Nashville area as a whole to handle the population increases?
personally, it needs to be upgraded as follows:
interstates 40, 24 and 65 need to have separated collector/disturber (or express and local lanes).
express lanes can be 4 lanes while local lanes can be 6. complete I-440 around to the other side of I-40 and have a I-265 to connect up from I-65 to the southwest to I-24 to the northwest (near clarksville)
force all thru traffic to funnel into I-840, I-440 and I-265
then have each of those, as well as briley parkway to be express and local laned as well.
with 4 express and 3 local lanes.
upgrade the downtown loop with removal of exits, to a express and local lane setup, 10 express and 12 local with bare minimum of 3 laned exit/entrance ramps. 1-2 of the local lanes can be exit ramps.
reconfigure all interchanges to match the widening.
if the city of nashville wants, they can have a middle bus/tram/metro corridor down the middle of each one.   :bigass: :-P

What'll get you your most bang for your buck would be completing I-840 and reconfiguring the downtown interchanges. That provides a much needed alternate route and addresses the biggest choke points. These are also the most possible to happen (but the most likely solution TDOT will develop is a half effort fix that's overrun in zero to five years). The biggest problem in downtown is right-of-way, followed by cost of construction. Briley Pky is fine as is.

The problem I see with express/local systems is ($) that you not only have to widen the roadway but you have to significantly adjust and add to system interchanges with all the different movements.

I could go more in depth but I'll see where this thread ends up first.
Title: Re: Nashville Infrastructure Upgrade
Post by: pianocello on November 14, 2022, 07:16:42 PM
My only experience with Nashville is passing through, I've never lived there or been there for more than enough time to stop for a meal. It's always been along I-65 to the north or I-24 in both directions, so I can't speak for I-40 at all.

With that in mind, I find it nuts that thru traffic on ALL THREE INTERSTATES has to enter on the left and leave on the right (or vice versa) not once but twice to stay on its route. Realigning those system interchanges could go a long way in reducing weaving movements and helping traffic move along, despite its super high cost.

Also, I feel like Briley Pkwy is underutilized as a northeast bypass route. When I've used it, there weren't a lot of vehicles on the road, which I found odd considering I've only used it when navigation directed me there to save time vs. I-24. If it had a better connection to I-24 or I-440 on the SE side, I wonder if that might take enough traffic to alleviate some of the downtown issues.
Title: Re: Nashville Infrastructure Upgrade
Post by: Tom958 on November 18, 2022, 05:30:30 AM
Quote from: pianocello on November 14, 2022, 07:16:42 PMWith that in mind, I find it nuts that thru traffic on ALL THREE INTERSTATES has to enter on the left and leave on the right (or vice versa) not once but twice to stay on its route. Realigning those system interchanges could go a long way in reducing weaving movements and helping traffic move along, despite its super high cost.

Have you ever drawn teen-roadgeek line diagrams of how that would work in practice? Consider I-40 between I-65 south and I-24 east, which was originally the I-40-65 overlap. The room required for the crossovers would greatly shorten the available weaving distance, thereby negating the reduction in weaving volumes brought about by moving the roadways to the optimum side. Plus, it would cost more and hopelessly complicate providing access to Lafayette Street and 2nd and 4th Avenues. They could've done a full braid there instead, in which case it'd be irrelevant which side the roadways were on. Might as well do what's cheapest. And if the forced weave was deemed to be adequate on that short stretch, it should be adequate on the longer overlaps as well.

Also, southbound I-65, former I-265, joins the ramp from westbound I-24 on the right and departs from the ramp to westbound I-40 on the right. It's not much, and it's not per the original layout, but it's something.

Title: Re: Nashville Infrastructure Upgrade
Post by: pianocello on November 19, 2022, 09:54:32 AM
Quote from: Tom958 on November 18, 2022, 05:30:30 AM
Quote from: pianocello on November 14, 2022, 07:16:42 PMWith that in mind, I find it nuts that thru traffic on ALL THREE INTERSTATES has to enter on the left and leave on the right (or vice versa) not once but twice to stay on its route. Realigning those system interchanges could go a long way in reducing weaving movements and helping traffic move along, despite its super high cost.

Have you ever drawn teen-roadgeek line diagrams of how that would work in practice? Consider I-40 between I-65 south and I-24 east, which was originally the I-40-65 overlap. The room required for the crossovers would greatly shorten the available weaving distance, thereby negating the reduction in weaving volumes brought about by moving the roadways to the optimum side. Plus, it would cost more and hopelessly complicate providing access to Lafayette Street and 2nd and 4th Avenues. They could've done a full braid there instead, in which case it'd be irrelevant which side the roadways were on. Might as well do what's cheapest. And if the forced weave was deemed to be adequate on that short stretch, it should be adequate on the longer overlaps as well.

In that area, I think what I would do is just shift the SB 24-WB 40 and NB 65-EB 40 ramps so they exit and enter on the left side. The gore points on both sides of the stretch line up vertically, so matching the elevations and bridges of the existing opposite ramps should be feasible without affecting weaving distance too much.

It can't happen without significant bridge work and road construction that would tie up the area for years, and for that reason likely will not happen. Also some ramps to 2nd/4th will be cut off, like you said. But I think flipping some of the system interchange ramps is physically possible, at the very least.

If I have time I might throw something in the Redesigning Interchanges thread. Or I'll try to redesign it and find something that throws a wrench in the whole thing  :sombrero:

Quote
Also, southbound I-65, former I-265, joins the ramp from westbound I-24 on the right and departs from the ramp to westbound I-40 on the right. It's not much, and it's not per the original layout, but it's something.

Good catch. I was looking at I-65's original routing for some reason.
Title: Re: Nashville Infrastructure Upgrade
Post by: civilengineeringnerd on December 27, 2022, 08:07:12 PM
if one is to redo the interchanges, they should consider at the very least removing the cluster of interchanges on the south part of the downtown loop and opting for something much more efficient. maybe have the one way roads go into a 2 laned ramp that bans access to the rest of the loop, while having one middle exit with broadway. of course TDOT has always been lead by old folks, so  :spin: