Tennessee

[I-39]

SR 397 (Mack Hatcher Pkwy) (parts Truck US 31/Truck US 431/Truck SR 96)
Project in Williamson County

State Route 397 (Mack Hatcher Parkway) Extension
Williamson County

Timeline
Transportation projects are developed in four phases: Planning and Environmental, Design, Right-of-Way and Construction. Due to the significant cost of construction, the Northwest Extension, from south of SR 96 to east of Hillsboro Road, has been divided into two smaller sections or phases.

Phase I Interim Improvement will include the construction of a two-lane roadway, all side road improvements, a multi-use path, and a single bridge crossing of the Harpeth River.
Phase II Ultimate Improvement will complete the four-lane divided facility, including a second bridge crossing of the Harpeth River.
Phase I is currently under construction.

Let to Contract:             12/7/2018
Contractor:                     EUTAW CONSTRUCTION COMPANY, INC.
Bid Price:                         $45,122,600.00
Est. Completion Date: NOVEMBER 2021

Phase II is not currently funded, and a timeline is not available.



*The Southwest Extension, from SR 6/US 31/Columbia Pike to SR 96, is NOT currently referenced in the Nashville Area MPO's 2040 Regional Transportation Plan and is NOT currently programmed to be constructed by TDOT or the city of Franklin at this time.

The only reason this was built/needed was because of the Westhaven subdivision. While in general, I like the growth that Franklin has experienced, Westhaven I have to admit was a poor idea and should never have been built. It is way too large and dense, and it is kind of in an awkward location surrounded by mostly rural land where nothing is likely to go.

This is one project I will give you that should not have been built. Money would have been better spent widening the SE leg and widening 31 down to I-840.

[Avalanchez71]

Westhaven is a nice place and has a hidden Kroger store.  I do think that it is out in the wrong area for sure.

[I-39]

At long last, TDOT has begun the reconstruction of the I-65/Bear Creek Pike (SR 99) interchange, which is long overdue and critically needed.

Plans include reconfiguring the interchange into a standard diamond, replacing the bridges with a single bridge (presumably with the width to accommodate a third lane in the future), widening Bear Creek Pike to five lanes in the interchange area and install traffic lights at the ramp terminals.

https://www.columbiadailyherald.com/story/news/2021/07/21/bear-creek-65-interchange-enhancement-project-breaks-ground-after-20-years-planning/8023055002/

Hopefully, after this is completed, Bear Creek Pike will be five laned to the Interstate. The future growth of Columbia will be along that corridor IMO.

[Avalanchez71]

At long last, TDOT has begun the reconstruction of the I-65/Bear Creek Pike (SR 99) interchange, which is long overdue and critically needed.

Plans include reconfiguring the interchange into a standard diamond, replacing the bridges with a single bridge (presumably with the width to accommodate a third lane in the future), widening Bear Creek Pike to five lanes in the interchange area and install traffic lights at the ramp terminals.

https://www.columbiadailyherald.com/story/news/2021/07/21/bear-creek-65-interchange-enhancement-project-breaks-ground-after-20-years-planning/8023055002/

Hopefully, after this is completed, Bear Creek Pike will be five laned to the Interstate. The future growth of Columbia will be along that corridor IMO.

That interchange is weird and one can get clobbered trying to get on.  There is a cemetary that is kind of in the way.  US 412 does not need to be four laned.  It is sufficient as-is.  There are climbing lanes and wide right-of-way.

[I-39]

At long last, TDOT has begun the reconstruction of the I-65/Bear Creek Pike (SR 99) interchange, which is long overdue and critically needed.

Plans include reconfiguring the interchange into a standard diamond, replacing the bridges with a single bridge (presumably with the width to accommodate a third lane in the future), widening Bear Creek Pike to five lanes in the interchange area and install traffic lights at the ramp terminals.

https://www.columbiadailyherald.com/story/news/2021/07/21/bear-creek-65-interchange-enhancement-project-breaks-ground-after-20-years-planning/8023055002/

Hopefully, after this is completed, Bear Creek Pike will be five laned to the Interstate. The future growth of Columbia will be along that corridor IMO.

That interchange is weird and one can get clobbered trying to get on.  There is a cemetary that is kind of in the way.  US 412 does not need to be four laned.  It is sufficient as-is.  There are climbing lanes and wide right-of-way.

There's just enough room for a NB on ramp without impacting the cemetery.

Sorry, but within the next 10-15 years, US 412/Bear Creek Pike will need to be five laned between US 31 and I-65. As Columbia/central Maury County grows, there is going to be increased traffic and development along the corridor. Not to mention the upgraded interchange will make I-65 more attractive to Columbia commuters as opposed to 31 to Saturn Parkway.

Columbia is pushing for it, and it's in the Nashville MPO 2045 transportation plan.

[triplemultiplex]

Having stayed at hotels at that Bear Creek exit many times, this is good news.  That interchange is woeful.  You can't see cross traffic from the ramp terminal coming from under I-65 very well and with no signals, it's not for the timid.  Then that accel lane northbound is very inadequate, especially with that tight loop.

Standard diamond will be better than the legacy interchange they've got, but if I had my druthers, it's a good spot for a DDI.

[codyg1985]

TDOT has in its August letting the I-65 widening project between TN 25 and TN 109. This will be the first of four sections that will complete the widening between Nashville and the Kentucky state line.

More info on the overall project can be found at https://www.tn.gov/tdot/projects/region-3/i-65-nashville-to-ky-state-line.html

[sprjus4]

TDOT has in its August letting the I-65 widening project between TN 25 and TN 109. This will be the first of four sections that will complete the widening between Nashville and the Kentucky state line.

More info on the overall project can be found at https://www.tn.gov/tdot/projects/region-3/i-65-nashville-to-ky-state-line.html

Don't tell Avalanchez 

[I-39]

Having stayed at hotels at that Bear Creek exit many times, this is good news.  That interchange is woeful.  You can't see cross traffic from the ramp terminal coming from under I-65 very well and with no signals, it's not for the timid.  Then that accel lane northbound is very inadequate, especially with that tight loop.

Standard diamond will be better than the legacy interchange they've got, but if I had my druthers, it's a good spot for a DDI.

It's not busy enough for a DDI. A standard diamond is fine here, as long as there is proper acceleration length on I-65. Getting rid of that dumb and dangerous loop ramp and making Bear Creek 5 lanes with traffic signals at the ramp terminals will do wonders.

Good locations for DDI's would be the Moore's Ln and SR 96 interchanges in Franklin. Those will be next up for reconstruction.

TDOT has in its August letting the I-65 widening project between TN 25 and TN 109. This will be the first of four sections that will complete the widening between Nashville and the Kentucky state line.

More info on the overall project can be found at https://www.tn.gov/tdot/projects/region-3/i-65-nashville-to-ky-state-line.html

Excellent. I hope they get the funding together and can start construction on the other three sections as soon as this is done. This widening is needed badly.

[Georgia]

TDOT has in its August letting the I-65 widening project between TN 25 and TN 109. This will be the first of four sections that will complete the widening between Nashville and the Kentucky state line.

More info on the overall project can be found at https://www.tn.gov/tdot/projects/region-3/i-65-nashville-to-ky-state-line.html

So glad to hear this, and it makes sense to fill in this short stretch of 2 lane compared to say, I-75 after Knoxville to the KY state line. 

[Daniel Fiddler]

I don't know how many people are interested in this, but Phase I of the I-40 six-laning project / exit 80 and exit 82 replacement in Jackson has been more or less complete.  Phase II is underway.

[Avalanchez71]

Having stayed at hotels at that Bear Creek exit many times, this is good news.  That interchange is woeful.  You can't see cross traffic from the ramp terminal coming from under I-65 very well and with no signals, it's not for the timid.  Then that accel lane northbound is very inadequate, especially with that tight loop.

Standard diamond will be better than the legacy interchange they've got, but if I had my druthers, it's a good spot for a DDI.

It's not busy enough for a DDI. A standard diamond is fine here, as long as there is proper acceleration length on I-65. Getting rid of that dumb and dangerous loop ramp and making Bear Creek 5 lanes with traffic signals at the ramp terminals will do wonders.

Good locations for DDI's would be the Moore's Ln and SR 96 interchanges in Franklin. Those will be next up for reconstruction.

TDOT has in its August letting the I-65 widening project between TN 25 and TN 109. This will be the first of four sections that will complete the widening between Nashville and the Kentucky state line.

More info on the overall project can be found at https://www.tn.gov/tdot/projects/region-3/i-65-nashville-to-ky-state-line.html

Excellent. I hope they get the funding together and can start construction on the other three sections as soon as this is done. This widening is needed badly.

.

The interchange rebuild at that exit is warranted. 

[Avalanchez71]

TDOT has in its August letting the I-65 widening project between TN 25 and TN 109. This will be the first of four sections that will complete the widening between Nashville and the Kentucky state line.

More info on the overall project can be found at https://www.tn.gov/tdot/projects/region-3/i-65-nashville-to-ky-state-line.html

Don't tell Avalanchez 

This is a disgrace and a love child of that dreadful gas tax increase that was rammed through.

[Daniel Fiddler]

TDOT needs to six-lane I-24 between exits 81 and 178, albeit 4 miles of that would probably be GDOT and not TDOT since it's in Georgia.  That section of interstate is congested very frequently.

It would not hurt to six-lane I-75 between exits 11 and 27 either.

[I-55]

TDOT needs to six-lane I-24 between exits 81 and 178, albeit 4 miles of that would probably be GDOT and not TDOT since it's in Georgia.  That section of interstate is congested very frequently.

It would not hurt to six-lane I-75 between exits 11 and 27 either.

Given that I-65 north of the TN-386 split has an AADT ~20,000 higher than I-24 and only now are they starting to widen it, I think I-24 won't be widened until its AADT tops 50-60k (if at all). Not to mention that segment of I-65 is 60 miles shorter.

I-75 might happen since it has similar traffic counts to I-65.

[hotdogPi]

I think I-24 won't be widened until its AADT tops 50-60k (if at all).

25K for two lanes is near record-setting for the entire country. Is there any reason why 50K for four lanes isn't the same?

[Daniel Fiddler]

I-24 has 40k - 50k already I believe.  And it will continue to rise.  It is over half of the connection between two fast-growing metropolitan areas, one of over 6 million and one of over 2 million, less than 250 miles apart.  I say get ahead of the problem before it gets worse, especially as slow as TDOT works.  FDOT and GDOT work fast.  97 miles of roadway would take FDOT or GDOT about a decade to complete.  It would take TDOT about half a century.

[I-55]

I-24 has 40k - 50k already I believe.  And it will continue to rise.  It is over half of the connection between two fast-growing metropolitan areas, one of over 6 million and one of over 2 million, less than 250 miles apart.  I say get ahead of the problem before it gets worse, especially as slow as TDOT works.  FDOT and GDOT work fast.  97 miles of roadway would take FDOT or GDOT about a decade to complete.  It would take TDOT about half a century.

It'll take them half a century to get to it, let alone do anything. I agree with your thinking but TDOT does not share Kentucky's, Georgia's, or Florida's attitude toward rural 6 lane interstates. If TDOT has a priority it is Nashville Metro and everything inside. They'll deal with concerns there before anywhere else.

[Daniel Fiddler]

I-24 has 40k - 50k already I believe.  And it will continue to rise.  It is over half of the connection between two fast-growing metropolitan areas, one of over 6 million and one of over 2 million, less than 250 miles apart.  I say get ahead of the problem before it gets worse, especially as slow as TDOT works.  FDOT and GDOT work fast.  97 miles of roadway would take FDOT or GDOT about a decade to complete.  It would take TDOT about half a century.

It'll take them half a century to get to it, let alone do anything. I agree with your thinking but TDOT does not share Kentucky's, Georgia's, or Florida's attitude toward rural 6 lane interstates. If TDOT has a priority it is Nashville Metro and everything inside. They'll deal with concerns there before anywhere else.

Well, Nashville and Memphis, although I agree.  Originally they were going to six-lane between exits 76 and 93 on I-40.  Then they truncated it to between exits 80 and 87, which made no sense to me.  They could have at the very least extended it west to 79.  Maybe they will, although I doubt it.

[wriddle082]

I-24 has 40k - 50k already I believe.  And it will continue to rise.  It is over half of the connection between two fast-growing metropolitan areas, one of over 6 million and one of over 2 million, less than 250 miles apart.  I say get ahead of the problem before it gets worse, especially as slow as TDOT works.  FDOT and GDOT work fast.  97 miles of roadway would take FDOT or GDOT about a decade to complete.  It would take TDOT about half a century.

It'll take them half a century to get to it, let alone do anything. I agree with your thinking but TDOT does not share Kentucky's, Georgia's, or Florida's attitude toward rural 6 lane interstates. If TDOT has a priority it is Nashville Metro and everything inside. They'll deal with concerns there before anywhere else.

Well, Nashville and Memphis, although I agree.  Originally they were going to six-lane between exits 76 and 93 on I-40.  Then they truncated it to between exits 80 and 87, which made no sense to me.  They could have at the very least extended it west to 79.  Maybe they will, although I doubt it.

TDOT's main priority isn't any of the metro areas.  It is one thing and one thing only: maintenance.  Making sure that what they already have built stays smooth and doesn't collapse.  If their priority were Nashville or Memphis, the cluster 24/65 duplex and the I-55 Crump interchange in Memphis would both be fixed.  In recent times, they have finished millions of dollars of work in Knoxville, and they're currently spending millions in Chattanooga, mainly to ensure that everything that was there wouldn't collapse.

[hbelkins]

I've long said I hated the mountain crossing just after you cross the state line, but even after you descend, the rest of the route on to Knoxville has an ancient feel to it.

For the terrain and the amount of traffic they carry, and to match up with what Kentucky has done, Tennessee needs to widen both I-65 and I-75 between the I-40 metro areas and the state line.

[froggie]

I think I-24 won't be widened until its AADT tops 50-60k (if at all).

25K for two lanes is near record-setting for the entire country. Is there any reason why 50K for four lanes isn't the same?

Two reasons.  First, the vast majority of busy 2-lane roads are not controlled-access.  Second, having a 2nd lane adds maneuverability in that faster traffic can pass slower traffic.  That said, the research that has gone into the Highway Capacity Manual indicates that the capacity effects of additional lanes are lessened once you get beyond 4 lanes per direction.

[webny99]

I think I-24 won't be widened until its AADT tops 50-60k (if at all).

25K for two lanes is near record-setting for the entire country. Is there any reason why 50K for four lanes isn't the same?

Two reasons.  First, the vast majority of busy 2-lane roads are not controlled-access.  Second, having a 2nd lane adds maneuverability in that faster traffic can pass slower traffic.  That said, the research that has gone into the Highway Capacity Manual indicates that the capacity effects of additional lanes are lessened once you get beyond 4 lanes per direction.

That's along the lines of what I was going to say:

Yes. There's a huge increase in throughput from two lanes to four because faster traffic can pass. With one lane almost always moving at a higher speed than the other, traffic doesn't get held up by a single car, and therefore moves significantly better. For roads with more than four lanes, the difference becomes more and more incremental for each added lane, since passing is allowed regardless.

[I-55]

I think I-24 won't be widened until its AADT tops 50-60k (if at all).

25K for two lanes is near record-setting for the entire country. Is there any reason why 50K for four lanes isn't the same?

Two reasons.  First, the vast majority of busy 2-lane roads are not controlled-access.  Second, having a 2nd lane adds maneuverability in that faster traffic can pass slower traffic.  That said, the research that has gone into the Highway Capacity Manual indicates that the capacity effects of additional lanes are lessened once you get beyond 4 lanes per direction.

That's along the lines of what I was going to say:

Yes. There's a huge increase in throughput from two lanes to four because faster traffic can pass. With one lane almost always moving at a higher speed than the other, traffic doesn't get held up by a single car, and therefore moves significantly better. For roads with more than four lanes, the difference becomes more and more incremental for each added lane, since passing is allowed regardless.

Diminishing Marginal Utility. Once you have so much of a thing, each extra item makes less of an impact for the user than the one before it.

[adventurernumber1]

A significant portion of interstate mileage in Tennessee is part of routes that carry lots of long-distance truck traffic. Among these are likely all of I-40 and I-81 in the state, most of I-75 and I-24 in the state, and I-65 through Metro Nashville and northward. Add that with all the regular traffic taking these roads (which is a good bit), and there's reasonable justification for a lot of widenings on Tennessee's interstates where needed (including rural stretches). The I-65 widening north of Nashville that has been approved is undoubtedly deserving. I may just be used to Georgia and Florida's massive prioritization of widening rural congested long-distance corridors. Sometimes I make the mistake of expecting the same thing from states like Tennessee and South Carolina that also have myriad important corridors with lots of traffic (see much of I-95, I-26, and I-85 in SC, etc.), but I do have to understand it's not always the same situation as with Georgia and Florida (funding may not be as good, and as noted upthread, some states just don't prioritize widening rural sections of interstate). All I'm saying is that the justification is definitely there, if a decision ever was made to widen many of these interstate segments (such as the recent approval for the I-65 widening), even if it's not always realistic (simply due to the limitations of funds, resources, etc.). These widenings are definitely not a bad idea. There's definitely good argument for widening I-24 between Murfreesboro and Chattanooga -- after all, that is sort of the connection between the massive trucking corridors of IN-KY-TN I-65 and GA-FL I-75. And widening I-75 north to Cleveland (Exit 27) is certainly a good idea as well. But Tennessee is only one state, and widening every single section of interstate part of these congested, long-distance corridors is not necessarily realistic or inexpensive, at least anytime soon. But bit by bit, there is definitely justification for it, as a lot of Tennessee's interstates carry significant AADT.

They are indeed pumping a lot of money and doing a good job with the road projects in Chattanooga (such as the reconstruction of the downtown US 27 freeway and the I-75/I-24 interchange reconstruction). As noted upthread, TDOT often prioritizes maintenance, but they also do a fine job with building new stuff. There's a lot to be done (not just widenings), but hopefully a lot of these widenings can happen in the near future to help ease congestion and in anticipation of future growth. The I-65 widening is another much-needed milestone (as is the I-40 widening in Jackson).