Re-shielding existing routes for a Bypass and Spur freeways in Nashville

[SFPredsFan]

840 already has some control city usage where it intersects but could use better distance signage on it for distance to those control cities.

Since 840 was completed has TDOT still just got Murfreesboro as the control city westbound on I-40 approaching 840W? That's all they had the last time I drove it but that was over 6 months ago. And did TODT ever add control cities on the eastbound approach to 840E from Memphis. There were none there just after TDOT opened it to traffic. It just really seems stupid to spend all this money on these Interstate grade highways and not add Interstate signage and the control cities of Memphis, Knoxville, Huntsville, and Chattanooga. What was the point to build the 840 bypass if your not going to include were they hell they are going. GPS doesn't help since it takes you the shortest route even if it takes you through the heaviest traffic at slower speeds.

[froggie]

Again, I think you guys are overestimating just how much traffic would divert.  Furthermore, there's enough latent demand in the Nashville core that whatever you DO manage to divert will just fill up again fairly quickly....exact same thing happened after I-65 was moved onto former I-265.

[SFPredsFan]

I don't think anybody's over estimating the potential diverted traffic at all. We all know most traffic is local, but if even half of the out of town thru traffic (especially truck traffic) could be diverted it would be a great help to the total gridlock on the downtown loop. Otherwise, what's the point to build and expand a bypass if it's not signed properly and it's just locals that use it. TDOT expanded the east loop of Briley to 8 lanes which only has 70k/day but has the capacity for over twice that. Why bother to expand it if almost every time I drive it there's hardly anybody on it while downtown loop is bumper to bumper for miles? Furthermore, I-265 was never considered a bypass but has always been an inner city route. Traffic speeds are much better when TDOT rerouted I-65 on to I-265. Which is exactly the point of what a few signs and renumbering a route can do to improve traffic flow.

[NE2]

Otherwise, what's the point to build and expand a bypass if it's not signed properly and it's just locals that use it.

Campaign contributions from developers.

[RoadWarrior56]

I have been using Briley Parkway as a bypass for I-24 through Nashville at certain peak hours for years.  Don't give out the secret by making it an interstate.  I love that most through traffic probably doesn't know about it.

[31E]

I've seen TDOT display that on the ITS signs on I-24 westbound on the east side of downtown but it's only when traffic is at a complete stop. I've also seen them display it on I-40 eastbound approaching Briley Parkway on the west side as "Heavy traffic ahead. To I-65 N use Briley Pkwy N".

My idea is to display it on VMS's during Rush Hour every day, say between 5-8 AM and 4-7 PM, or whatever the hours are (I avoid Nashville during the morning and evening commutes). That would be more effective than displaying it after the traffic is already at a standstill. What Nashville really needs is more road space, since obviously the current demand is too much for the current freeways - IMO most Nashville freeways should have roughly double the lanes they currently have, and a commuter rail network should be created. That's the only solution that's going to be effective long-term, and it would whip the congestion problems . Adding in a subway system would be even better, but that's not needed at this point.

3 lanes in each direction is the norm for a Nashville freeway, so doubling it would create a norm of 6 lanes, which is large but not unreasonable. In fact I-65 between Briley Pky and Old Hickory Blvd is 6+ lanes in each direction right now. As an aside, I-65 just north of Briley Parkway is the widest stretch of freeway in Middle Tennessee - 18 lanes total if you include parallel ramps.

EDIT: Or you could eliminate all those random or sudden lane drops across the Nashville area. That alone would be a big improvement.

[froggie]

@SFPreds:  what you will find is that whatever capacity you open up in the core will quickly be swallowed.  When I-65 was moved to the former I-265 in 2000, there was a bit of a drop on the standalone segments of I-24 and I-40, but it took less than 3 years for traffic on I-24 to bounce back up to what it was before I-65 moved.  You will have the same situation with whatever diversion you manage to implement here with Briley.

@31E: How do you propose paying for all that widening?  Especially where it will involve land acquisition?  Freeways are not cheap anymore.

[SFPredsFan]

31E...actually other than I-440, 24NW, parts of 40W, and the downtown loop, all the freeways in Nashville are 8 lanes or more and are all under capacity other than I-440 and a few miles of 40W. It's the downtown loop that causes backups in all directions. That was a design flaw from the 60's of all the weaving from one Interstate to another every 2 miles and some of the horrible exit/entrance ramps. The last couple of miles of 40E and 65S will be completed to 8 lanes within 2 years all the way out to SR840. It would be impossible to expand the freeways in Nashville where they are 8 lanes or more now due to budget and ROW constraints. I will agree the ITS should display alternative routes but I would display it during all the daytime hours since you never know when traffic will get bogged down on the downtown loop. Same goes with SR840. I would put ITS signs on the east and west bound approaches to 840 and have them say "Extreme traffic in Nashville. I-40 Thru traffic take 840" all day long. That was another one of my suggestions to TDOT and they thought it was an excellent idea to encourage thru traffic to use it.

Subway and trains would be nice but Nashville is another million people or so from making that happen. The Nashville Star is a money pit and requires heavy subsidies to keep running. The worst mistake this country ever made was to let the auto and oil lobby rip up all the street car tracks that ran through neighborhoods so that buses would have to be used.   

[SFPredsFan]

froggie...I'm not sure what your point is. Are you saying don't bother to divert traffic to bypasses because the congestion you just free up will eventually just get congested again? That make no sense if I read you correctly.
My biggest gripe is that so much traffic could be diverted to much safer routes especially around bottleneck construction zones.   

[froggie]

I'm not saying don't bother.  Your control city idea makes sense.  I'm just being realistic about the likely effects/expectations afterwards.

But yes, if your goal is to reduce congestion on I-24 in the core, the result will be short-lived at best.

And the reason actually makes a lot of sense.  You move some longer-distance traffic off I-24.  Locals see that I-24 is less busy and flock to it, with the end result being that I-24 fills right back up fairly quickly.  As I mentioned before, we saw it when they diverted I-65 to the former I-265 12 years ago.

[31E]

Even if the capacity is completely soaked up by latent demand, you'd still be moving more vehicles through, so all is not lost. Like I said, the only viable long-term fix is to provide more road space across the board, since there isn't enough to go around for the demand (latent and otherwise) that is there. Adding commuter rail would also ease traffic, and I don't care whether it turns a profit or not - do we ever expect Interstates to be profitable?

31E...actually other than I-440, 24NW, parts of 40W, and the downtown loop, all the freeways in Nashville are 8 lanes or more and are all under capacity other than I-440 and a few miles of 40W.

I was primarily referring to the downtown area in my post.

It would be impossible to expand the freeways in Nashville where they are 8 lanes or more now due to budget and ROW constraints.

The status quo in Tennessee is to spend $30 billion a year and let transportation infrastructure languish due to "lack of funds", which is ridiculous if you ask me. There is enough room to expand almost every freeway in Davidson County without destroying any structures, even if additional ROW would have to be acquired. I won't get into the political arena here, except to say that providing excellent transportation infrastructure should be considered top priority by all states. Let the state legislatures figure out where to get the money for the improvements  .

I will agree the ITS should display alternative routes but I would display it during all the daytime hours since you never know when traffic will get bogged down on the downtown loop. Same goes with SR840. I would put ITS signs on the east and west bound approaches to 840 and have them say "Extreme traffic in Nashville. I-40 Thru traffic take 840" all day long. That was another one of my suggestions to TDOT and they thought it was an excellent idea to encourage thru traffic to use it.

That's an even better idea, since there are random traffic jams at all times of day in downtown.

[Avalanchez71]

Otherwise, what's the point to build and expand a bypass if it's not signed properly and it's just locals that use it.

Campaign contributions from developers.

Bingo.  This poster knows of what he speaks.  SR 840 was not built with our funds for out-of-towners to use.  It was built for local land development and it has been a tremendous success in Rutherford County; however, strangely there are few services directly off of it.
Post Merge: August 27, 2013, 08:53:20 PM

Otherwise, what's the point to build and expand a bypass if it's not signed properly and it's just locals that use it.

Campaign contributions from developers.

Bingo.  This poster knows of what he speaks.  SR 840 was not built with our funds for out-of-towners to use.  It was built for local land development and it has been a tremendous success in Rutherford County; however, strangely there are few services directly off of it.

Follow the money trail folks.  The reason why the state roads are signed as such as they are maintained with local funds.  Furthermore the through traffic is run through town to get the folks to stop and spend money here.  SR 840 was built for local land development.  It serves the locals so it is easier for the locals to commute.  There are virtually no services along the SR 840 corridor.  Could that change with a shielding as an interstate, no doubt.  Just look at the politics and money and not just the how nice it would look with a red, white and blue.

[froggie]

@31E:  that was not my quote (it was SFPreds), though I agree with the premise made.  Furthermore, freeways actually begin to lose efficiency once they're expanded beyond 8-10 lanes (documented in the Highway Capacity Manual).

[31E]

Per-lane efficiency (assuming that's what you're talking about) may drop, but a 12-lane freeway still accommodates a lot more cars than an 8-lane freeway, and the added capacity is needed in the region. If I had total power, the downtown loop would have priority, and the bulk of that is 6 lanes, and no part of it is more than 8 lanes.

And I'm sorry that I mixed up your quotes . Besides, we're veering into fictional highways territory with talk of total power and my laundry list of improvements, so let's get back to the original topic. The point about local funding is a good one, but locally-funded roads can be added to the Interstate system as non-chargeable mileage IIRC.

[hbelkins]

Maybe there need to be some VMSes with travel times mentioned.

Say, on I-40 westbound approaching Lebanon:

Time to Dickson
Via I-40 west: 65 minutes
Via SR 840 west: 45 minutes

(Those times are just guesses).

And do something similar for the approaches to the Briley.

[SFPredsFan]

hbelkins....TDOT does that sometimes on other routes and it's nice info. The only problem I see with that for 840 is when they display a quicker time thru Nashville, traffic could get bogged down or a crash could happen just a few minutes after you pass the ITS sign and then it's too late to get take the bypass so you'll be stuck in a traffic jam. Your time savings, or what you thought would be, would then be a 2 hour ordeal navigating around wrecks and/or traffic jams. Now if TDOT displayed a quicker time permanently via 840 that would work especially since the higher speed limits and less traffic would negate the extra 17 miles by taking 840. When I made that suggestion to TDOT to display "Extreme traffic in Nashville. I-40 Thru traffic use 840" at all times during the day, a TDOT official said what if there is no extreme traffic in Nashville. I told him that's easy, just lie about it. It's not like anybody's going to know it would've been smooth sailing thru Nashville since they took the bypass anyways. They all just laughed and said good point. 

[froggie]

It's not like anybody's going to know it would've been smooth sailing thru Nashville since they took the bypass anyways.

This will increasingly not be the case, as people rely more and more on their GPS's, which are now incorporating traffic data into their logarithms.

As for travel time VMS, I'd think a better option for those would be for 40 vs 440.  840 is too far out.  Then there's the case where there, compared to the 130K-some on 40 in the downtown core, only a small percentage of that is actually through traffic with an origin and/or destination beyond 840.

[mrsman]

In my opinion, interstate shields should only be used on interstate quality roads.

However, I also think that if a freeway would be a great fit to the interstate system, except that the road doesn't meet
interstate standards, that road should have a state highway number that fits in to the numbering system.  Nashville already
has SR 840.  Other examples include SR 470 in Denver, SR 210 east of Los Angeles, SR 878 near JFK Airport in New York.

Briley Parkway should be renumbered as TN 224 (or 424) and signed with control cities of Memphis, Paducha, Louivsille, and Knoxville, along with other appropriate local control cities. 

Ellington Pakway should be signed as TN 365 with guidance signage that says: Central Nashville, East Bank, Use 365.

[hbelkins]

Briley Parkway should be renumbered as TN 224 (or 424) and signed with control cities of ... Paducha

Except Tennessee uses Clarksville, not Paducha, for I-24. And they don't use Paducah either. 

[SFPredsFan]

mrsman....Glad you agree with my suggestions to TDOT. SR840 and SR155 are already are built to Interstate standards so TDOT should just request they be added to the Interstate system and add the proper control city signage. As mentioned before, a few miles of SR155 on the west loop have some narrow shoulders but TDOT could easily get a waiver from the FHA. I'd still love to see TDOT upgrade the SE loop of SR155 from I-40 to I-24 and Ellington Parkway's ridiculous ramps at it's southern end . They're going to have to widening them to at least 6 lanes probably sooner than later so TDOT could upgrade them then. I make sure to check the TDOT Smartway camera website several times everyday and especially before I head to work and home. I'm still amazed at how SR155 and Ellington Parkway are ghost roads yet I-24 from the I-24/40 east split to the end of I-24/65 north split is just barely moving ALL DAY LONG. I-65 back to I-40 on the west downtown loop is just as bad. I've sit for 30 minutes in that traffic before and not moved even without a wreck ahead. SR155 on the Briley Parkway east loop averages 66k/day yet it has been widened to 8 lanes and can handle more than twice that with the Midwest and Southeast bound traffic. That's why I'm so adamant about upgrading the SE part of Briley and adding Chattanooga for a control city on the north and NW side and Louisville and Clarksville and the SE side. Sure, most traffic is local, but it's total bullshit for out of town thru travelers to get stuck in our traffic jams and add to it because TDOT hasn't signed any controls cities and promoted use of our bypasses.

[SFPredsFan]

Except Tennessee uses Clarksville, not Paducah for I-24.

I remember when St.Louis was the control city for I-24 westbound in Nashville even though I-24 didn't even reach it. At over 310 miles that had to be one of the longest distance control cities east of the Mississippi.

[froggie]

As mentioned before, a few miles of SR155 on the west loop have some narrow shoulders but TDOT could easily get a waiver from the FHA.

Not really.  Given past and current precedent, the roadway must be fully up to Interstate standards before FHWA will accept it as a non-chargeable Interstate.  It would have to be a very significant engineering reason (and cost is NOT considered an option) for FHWA to grant a waiver.

[SFPredsFan]

Not really.  Given past and current precedent, the roadway must be fully up to Interstate standards before FHWA will accept it as a non-chargeable Interstate.  It would have to be a very significant engineering reason (and cost is NOT considered an option) for FHWA to grant a waiver.

Your kidding right???? I can name at least a dozen Interstates and sections that are not up to standards off the top of my head that were granted waivers. That's not even including I-180 in Cheyenne that is at grade it's entire route. The Sure Kill in Philly doesn't even have shoulders on the inside or outside lanes, I-70 barely has an inside shoulder thru St. Louis, and WTF is up with I-80 Breezewood, PA? Most older Interstates that were built or added later in the Northeast have horrible off/on ramps that could never be considered Interstate standards but were granted waivers or grandfathered into the system. DOT has changed the specs since the early days of Interstate building, but they've granted plenty of waivers since then. I-22 is the one example that I can think of where they won't let MSDOT sign it until they get some bridges, shoulders, and interchanges up to date and they made TDOT take down the I-124 signs in Chattanooga until it is up to standards. That's what TDOT told me anyways along with the fact there was a lot of confusion for out of town thru traffic taking I-124 by mistake so they put up US27 shields thru downtown. TDOT did say they might resign it and ask to extend it to Dunlap via SR111, with Cookeville as the control city, after they're finished with the Rebuild US 27 projects thru and north of downtown.

But back to SR155 west loop, TDOT told me when the westside interchange with I-40 was completed, that made the entire northern loop of SR155 up to Interstate standards and eligible to apply for I-Xwhatever status. After looking up the criteria for Interstate Highway standards, all that's required is 10' outside shoulders and 4' inside shoulders which SR155 already has on it's entire loop north of I-40.

[froggie]

Those were all Interstates that were part of the original 41,000 mile plan (yes, even I-180 in Cheyenne)...a little different situation there.  Every new Interstate added since the 1980s (including I-39, I-88, I-22, I-355 Chicago, the new North Carolina Interstates, etc etc) has had to be up to standards first, *ESPECIALLY* in the case of non-chargeable Interstates like your Tennessee proposal would be.

Also, shoulder standard for urban areas or where there is median divider is a 10ft inside shoulder, not 4ft.

It should also be noted that standards change over time.  For example, prior to 1967, it was not required to carry the shoulders across bridges.  This is why you only see a 2ft shoulder on some bridges on the older rural Interstates.  Some bridges have been retrofitted since then as they've come up for bridge redecking projects, but several still remain, especially on longer bridges (Vermont is full of them on I-89 and I-91, also several remain on I-59 in Mississippi).

[SFPredsFan]

According to AASHTO, these standards are, as of July 2007, as follows:

Shoulder width: Minimum outside paved shoulder width of 10 feet (3.05 m) and inside shoulder width of 4 feet (1.22 m). With three or more lanes in each direction, the inside paved shoulder should be at least 10 feet (3.05 m) wide. If truck traffic is over 250 Directional Design Hour Volume, shoulders at least 12 feet (3.66 m) wide should be considered. In mountainous terrain, 8 feet (2.44 m) outside and 4 feet (1.22 m) inside shoulders are acceptable, except when there are at least four lanes in each direction, in which case the inside shoulders should also be 8 feet (2.44 m) wide.

SR155 east loop easily meets that. SR155 west loop is 2 lanes in each direction so it meets their criteria by their own standards. Now the "If truck traffic is over 250 Directional Design Hour Volume, shoulders at least 12 feet (3.66 m) wide should be considered", I read that as a consideration when building or upgrading a highway but not an absolute requirement with existing highways otherwise they would have said so as picky as DOT is about Interstate designation. TDOT did say when SR155 west loop was finally completed back in the 80's they built it to Interstate standards at that time and actually had 840 in mind before Gov. Alexander pushed SR840 to be built by TDOT as the south bypass for Nashville.

And no, not all Interstates have been grandfathered. Several others were added or built after the original Interstate route plans. If you can find an update to 2007 AASHTO regulations let me know. I couldn't find any updates since then.