Tennessee

[Rothman]

Tennessee is finally eliminating the 65 mph / 55 mph truck speed limit on I-81 south of Bristol. The speed limit will be increased next week to 70 mph for all vehicles.

https://x.com/marknagitdot/status/1763201428124815823

It was all done in an effort to get the air quality in EPA compliance for the metro areas where it wasn't in compliance.  Knoxville, Chattanooga, and Memphis metro areas also had these ridiculous speed limit decreases, while Nashville instead expanded emissions testing to the outlying counties so their speed limits never went down from 70 to 65 once you entered an outlying county.  I know that Metro Knoxville has raised their limits back to 70, but I can't remember whether or not Chattanooga or Memphis have done the same.

*citation needed*

[wriddle082]

Tennessee is finally eliminating the 65 mph / 55 mph truck speed limit on I-81 south of Bristol. The speed limit will be increased next week to 70 mph for all vehicles.

https://x.com/marknagitdot/status/1763201428124815823

It was all done in an effort to get the air quality in EPA compliance for the metro areas where it wasn't in compliance.  Knoxville, Chattanooga, and Memphis metro areas also had these ridiculous speed limit decreases, while Nashville instead expanded emissions testing to the outlying counties so their speed limits never went down from 70 to 65 once you entered an outlying county.  I know that Metro Knoxville has raised their limits back to 70, but I can't remember whether or not Chattanooga or Memphis have done the same.

*citation needed*

Here's an article from way back in the dark ages of 2007 when our economy started to go in the s*****r and they first implemented these ridiculous speed limit reductions that have been universally ignored:

https://www.ccjdigital.com/business/article/14905129/i-81-speed-limit-drops-in-east-tennessee

TDOT's news release archive only goes back to 2015 so I can't find any specific articles from them about it, but I do remember them having press releases back then about the speed limit lowering in Memphis, Chattanooga, and Knoxville metros, and I suppose Tri-Cities was included as well.

[MikeTheActuary]

I know that Metro Knoxville has raised their limits back to 70, but I can't remember whether or not Chattanooga or Memphis have done the same.

The most recent Streetview images have westbound I-40 dropping to 65 between the Shelby County line and the I-269/TN 385 interchange.

I didn't check the entire length of I-269 in Tennessee, but the southernmost section of northbound 269 (including parts in Shelby County) is posted at 70, dropping to 65 at milepost 4 (in Fayette County, just north of TN57), while southbound 269 goes to 70 just before the Mississippi state line.

I-40 and I-55 are congested enough for a lower speed limit to be plausible.  I-269 is the real test for whether environmental speed limits are still in place; the inconsistency of NB and SB speed limits between Exit 1 and Exit 3 on 269 doesn't make sense.

[Rothman]

Tennessee is finally eliminating the 65 mph / 55 mph truck speed limit on I-81 south of Bristol. The speed limit will be increased next week to 70 mph for all vehicles.

https://x.com/marknagitdot/status/1763201428124815823

It was all done in an effort to get the air quality in EPA compliance for the metro areas where it wasn't in compliance.  Knoxville, Chattanooga, and Memphis metro areas also had these ridiculous speed limit decreases, while Nashville instead expanded emissions testing to the outlying counties so their speed limits never went down from 70 to 65 once you entered an outlying county.  I know that Metro Knoxville has raised their limits back to 70, but I can't remember whether or not Chattanooga or Memphis have done the same.

*citation needed*

Here's an article from way back in the dark ages of 2007 when our economy started to go in the s*****r and they first implemented these ridiculous speed limit reductions that have been universally ignored:

https://www.ccjdigital.com/business/article/14905129/i-81-speed-limit-drops-in-east-tennessee

TDOT's news release archive only goes back to 2015 so I can't find any specific articles from them about it, but I do remember them having press releases back then about the speed limit lowering in Memphis, Chattanooga, and Knoxville metros, and I suppose Tri-Cities was included as well.

Wonder if the reduction had the intended environmental benefits, then.

Having an non-attainment area means you get apportioned Congestion Mitigation and Air Quality funding, which is a double-edged sword with more edge on the "what a pain" side, due to strict eligibility requirements (although the funds can be swapped with other apportionments...until FHWA doesn't like the amount and slaps the DOT's wrist and environmental groups sue).  Have to spend the money one way or another and get in a little trouble if you don't.

(personal opinion emphasized)

[wriddle082]

Tennessee is finally eliminating the 65 mph / 55 mph truck speed limit on I-81 south of Bristol. The speed limit will be increased next week to 70 mph for all vehicles.

https://x.com/marknagitdot/status/1763201428124815823

It was all done in an effort to get the air quality in EPA compliance for the metro areas where it wasn't in compliance.  Knoxville, Chattanooga, and Memphis metro areas also had these ridiculous speed limit decreases, while Nashville instead expanded emissions testing to the outlying counties so their speed limits never went down from 70 to 65 once you entered an outlying county.  I know that Metro Knoxville has raised their limits back to 70, but I can't remember whether or not Chattanooga or Memphis have done the same.

*citation needed*

Here's an article from way back in the dark ages of 2007 when our economy started to go in the s*****r and they first implemented these ridiculous speed limit reductions that have been universally ignored:

https://www.ccjdigital.com/business/article/14905129/i-81-speed-limit-drops-in-east-tennessee

TDOT's news release archive only goes back to 2015 so I can't find any specific articles from them about it, but I do remember them having press releases back then about the speed limit lowering in Memphis, Chattanooga, and Knoxville metros, and I suppose Tri-Cities was included as well.

Wonder if the reduction had the intended environmental benefits, then.

Having an non-attainment area means you get apportioned Congestion Mitigation and Air Quality funding, which is a double-edged sword with more edge on the "what a pain" side, due to strict eligibility requirements (although the funds can be swapped with other apportionments...until FHWA doesn't like the amount and slaps the DOT's wrist and environmental groups sue).  Have to spend the money one way or another and get in a little trouble if you don't.

(personal opinion emphasized)

I wanna say that none of the areas that had to reduce their speed limits were requiring emissions or OBD II and gas cap testing, so they implemented that along with the speed limit reductions.  But Nashville had actually reached attainment during that time because certain air polluting factories and/or coal fired power plants either closed or reduced their emissions, not to mention that they have required emissions testing since the early 80's.   Now I think the industrial air pollution has started to go down in the Tri-Cities, so the 70-to-65 speed limit reduction is going away.  And more fuel efficient ICE vehicles as well as hybrids and electrics have also helped matters.  Possibly even telecommuting as well.  Or it could even depend on which party is in the Oval Office.

[BlueRidge]

Speed limits on I-26 and I-81 in Sullivan County dropped in 2007. TDOT implemented the change at the request of the Sullivan County Commission, who voted in favor of the action at the urging of the Kingsport Municipal Planning Organization.

Relevant quote:

The Kingsport Metropolitan Planning Organization asked the County Commission to seek the speed limit change from TDOT. The goal: reduce vehicle emissions, thereby improving air quality, with the goal of bringing Sullivan County into attainment with the Environmental Protection Agency's federal air quality health standard for ozone. Sullivan County and portions of the East Tennessee Valley are currently categorized by the EPA as non-attainment areas.

"County governments are looking at ways to improve air quality to meet EPA standards," said TDOT Chief of Environment and Planning Ed Cole. "A study conducted by the Federal Highway Administration shows that reducing truck speed limits by 10 miles per hour can reduce the nitrogen oxide emission factor by approximately 18 percent or more per truck. If we get reductions anywhere close to that level it will be worth it."

"According to studies by the Tennessee Department of Environment and Conservation's Division of Air Pollution Control, reduction of interstate truck speed limits is among the most effective measures we can take to assure the Tri-Cities attains and maintains attainment with the National Ambient Air Quality Standard for ground-level ozone," said Bill Sorah, chairman of the Ozone Action Partnership for Northeast Tennessee. "This action fits in with our Early Action Compact with EPA, which has allowed our counties to avoid classification as non-attainment. Non-attainment is a label we want to avoid. Not only would it mean our air quality does not meet the standards, but it would also create an impediment to economic development."

Source: https://www.timesnews.net/news/local-news/tdot-lowers-i-26-i-81-speed-limits-in-sullivan/article_57387059-8e21-50bf-9588-88b88a1aa02e.html

As an aside, I can assure you that Sullivan County of all places would not have pursued this change solely to appease a three-letter federal agency.

[sprjus4]

I'm curious if I-26's speed limit will rise back to 70 mph at all... arguably, the entire highway (except through Johnson City) from the Virginia state line (the small stretch that's solely US-23) to the North Carolina state line could reasonably be signed as 70 mph.

[wriddle082]

I'm curious if I-26's speed limit will rise back to 70 mph at all... arguably, the entire highway (except through Johnson City) from the Virginia state line (the small stretch that's solely US-23) to the North Carolina state line could reasonably be signed as 70 mph.

The Tennessee side of the ridge going towards Sam's Gap has been posted at 55 or 50 ever since they opened it up in 1996.  The North Carolina side was built to a higher standard with fewer sharp curves and gentler grades, and I believe has been signed at 65/trucks 55 since it opened in 2004.  I would say that North Carolina could get away with upping it to 70 with little consequence, but I have struggled to even go that fast in Tennessee since it's steeper and a little curvier.

[froggie]

I'm curious if I-26's speed limit will rise back to 70 mph at all... arguably, the entire highway (except through Johnson City) from the Virginia state line (the small stretch that's solely US-23) to the North Carolina state line could reasonably be signed as 70 mph.

I would disagree with that.  You could MAYBE get away with 70 down to Unicoi or even Erwin.  But past that Billy's right...a lower design standard with a narrow median and a lot of curves on the uphill climb to the state line.  60 may be doable.  65 would be pushing it, especially for the trucks.  70 is out of the question.

[sprjus4]

I'll correct my statement to say MM 24 (south of Johnson City) to MM 42 (state line is MM 54). That segment is higher design standard and posted at 65 mph.

It has been years since I've been on that southern part (12 miles) but you're correct in that it has a lower design speed after looking at it on Google Maps. The limit already drops to 60 mph there.

Additionally, MM 18 to MM 1 could also go from 65 mph to 70 mph.

So in total 17 miles north of Johnson City, and 18 miles south of Johnson City.

[sprjus4]

The Tennessee side of the ridge going towards Sam's Gap has been posted at 55 or 50 ever since they opened it up in 1996.

It looks like Tennessee modified the speed limit about 10 years ago to go from 55 mph up to 60 mph / 55 mph truck, then it drops to 55 mph / 50 mph truck closer to the line.

NC could go to 70 mph, but they are very reluctant with anything over 65 mph in that part of the state (except a portion of I-40 and some of US-74 going to Charlotte where it's flatter).

[webny99]

I-24 heading N/WB out of Nashville to the KY line seems to have been exceptionally congested for most of the day yesterday and again this morning. Can anyone from the area comment if this is strictly eclipse related, or is there something else going on? Either way it would appear that widening is sorely needed here, does TN have any plans to widen this segment?

[sprjus4]

I-24 heading N/WB out of Nashville to the KY line seems to have been exceptionally congested for most of the day yesterday and again this morning. Can anyone from the area comment if this is strictly eclipse related, or is there something else going on? Either way it would appear that widening is sorely needed here, does TN have any plans to widen this segment?

There was eclipse traffic everywhere in the midwest & northeast yesterday, that's not a good metric to base off of. I-79 between Erie and Pittsburgh had about 100 miles (!) of standstill / slow moving traffic southbound after the eclipse - that highway would never warrant 6 lanes on any other day.

[webny99]

I-24 heading N/WB out of Nashville to the KY line seems to have been exceptionally congested for most of the day yesterday and again this morning. Can anyone from the area comment if this is strictly eclipse related, or is there something else going on? Either way it would appear that widening is sorely needed here, does TN have any plans to widen this segment?

There was eclipse traffic everywhere in the midwest & northeast yesterday, that's not a good metric to base off of. I-79 between Erie and Pittsburgh had about 100 miles (!) of standstill / slow moving traffic southbound after the eclipse - that highway would never warrant 6 lanes on any other day.

Of course, but this was occurring on Sunday, which no doubt had some eclipse traffic but not nearly as much as Monday elsewhere around the country. I'm not saying to base anything off of it, just wondering since it was that bad if it was already known to be a problem stretch.

[wriddle082]

I-24 heading N/WB out of Nashville to the KY line seems to have been exceptionally congested for most of the day yesterday and again this morning. Can anyone from the area comment if this is strictly eclipse related, or is there something else going on? Either way it would appear that widening is sorely needed here, does TN have any plans to widen this segment?

There was eclipse traffic everywhere in the midwest & northeast yesterday, that's not a good metric to base off of. I-79 between Erie and Pittsburgh had about 100 miles (!) of standstill / slow moving traffic southbound after the eclipse - that highway would never warrant 6 lanes on any other day.

Of course, but this was occurring on Sunday, which no doubt had some eclipse traffic but not nearly as much as Monday elsewhere around the country. I'm not saying to base anything off of it, just wondering since it was that bad if it was already known to be a problem stretch.

Prior to my moving away from Greater Nashville in 2010, I had known I-24 towards Clarksville to be sluggish, but not as bad as you're describing.

Two Fridays ago, I drove from St. Louis to Nashville via the traditional route of 64 E to 57 S to 24 E. The drive was uneventful until I passed Exit 4 in Clarksville (traditionally the main exit for Clarksville) around the 2-3 PM timeframe.  It was moving mostly just below the speed limit in both lanes, with occasional inexplicable sudden slowdowns.  I got so frustrated with it that I bailed at Exit 31 and cut over to US 41A, as my next turn was to go Briley Pkwy around the west side, so I ended up saving a few miles.

Should a 40-mile stretch of interstate linking the largest city in the state with the fifth largest city in the state be at least six lanes?  Absolutely!  Especially since a 29-mile stretch of that same interstate connecting the largest city in the state with the sixth largest city in the state has been eight lanes for nearly 20 years.

I do believe there are plans to eventually get I-24 widened to Clarksville that have been outlined in the IMPROVE Act, but right now priority #1 is finishing the widening of I-65 coming down from Kentucky, and then fixing other issues around Spring Hill, Chattanooga, and west of Knoxville.

Also, I noticed during my trip that parts of 24 just east of Clarksville are in the process of being resurfaced, so you could have also been seeing traffic caused by (poorly timed) lane closures related to that.