The Transportation and Mass Transit Megathread

[PaulChinetti]

I think a train/monorail/light rail from the airport to say the convention center or even to somewhere around the titans stadium  would be a monumental hit. 

The convention center, airport, and Titans could fund it and any other businesses that wanted it, I imagine hotels would love it too. 

 

Talk about density right were that ended, it would be all skyscrapers and then from there it could continue wherever. 

[Luvemtall]

^^^^ that’s what I’m thinking ^^^ spot on!

[Nathan_in_DC]

Interesting article by The Atlantic today on how blame for dangerous conditions on roadways has been unfairly placed almost entirely on drivers. The article argues that car manufacturers have deflected any blame for danger from the "bigger, taller" SUV and pickup arms race, while poor road designs that all but guarantee dangerous conditions continue to plague urban and rural areas alike. I do wish that there was more discussion of the poor state of driver training in the US, the mishmash of rules, and ineffective enforcement that is hobbled by pro-driving lobbies keeping effective tools from being utilized, but overall a very interesting read.

Quote

 

https://www.theatlantic.com/ideas/archive/2021/11/deadly-myth-human-error-causes-most-car-crashes/620808/

More than 20,000 people died on American roadways from January to June, the highest total for the first half of any year since 2006. U.S. road fatalities have risen by more than 10 percent over the past decade, even as they have fallen across most of the developed world. In the European Union, whose population is one-third larger than America’s, traffic deaths dropped by 36 percent between 2010 and 2020, to 18,800. That downward trend is no accident: European regulators have pushed carmakers to build vehicles that are safer for pedestrians and cyclists, and governments regularly adjust road designs after a crash to reduce the likelihood of recurrence.

But in the United States, the responsibility for road safety largely falls on the individual sitting behind the wheel, or riding a bike, or crossing the street. American transportation departments, law-enforcement agencies, and news outlets frequently maintain that most crashes—indeed, 94 percent of them, according to the most widely circulated statistic—are solely due to human error. Blaming the bad decisions of road users implies that nobody else could have prevented them. That enables car companies to deflect attention from their decisions to add heft and height to the SUVs and trucks that make up an ever-larger portion of vehicle sales, and it allows traffic engineers to escape scrutiny for dangerous street designs.

 

 

[PleinNash]

There’s been a lot of discussion about capping interstates 40/65 where they pass Church St/Broadway/ Demonbruen/ 12th Ave to make a park. 
 

Has there been any talk about double decking the interstate there to double the interstate capacity in such a congested spot? The lower level could be a bypass of sorts while the upper level could handle business traffic intersecting with those crossing streets, perhaps even exiting directly into the Reed District and the Beaman site on one side and Nashville Yards on the other? 
 

Probably a simple thought that would be much harder to implement? 

 

 

Edited December 1, 2021 by PleinNash

[Luvemtall]

4 minutes ago, PleinNash said:

There’s been a lot of discussion about capping interstates 40/65 where they pass Church St/Broadway/ Demonbruen/ 12th Ave to make a park. 
 

Has there been any talk about double decking the interstate there to double the interstate capacity in such a congested spot? The lower level could be a bypass of sorts while the upper level could handle business traffic intersecting with those crossing streets. 
 

Probably a simple thought that would be much harder to implement? 

 

 

Sounds like a interesting idea. I’ve been wondering how if they capped that area , would all those exits work. They are basically one right after another, doesn’t leave much area for green space to connect .   Maybe a combination of your idea and capping would work. Lower level express lanes with no exits then a second level with exits for local traffic all capped! Sort of a double layer tunnel.

[Nathan_in_DC]

11 minutes ago, Luvemtall said:

Sounds like a interesting idea. I’ve been wondering how if they capped that area , would all those exits work. They are basically one right after another, doesn’t leave much area for green space to connect .   Maybe a combination of your idea and capping would work. Lower level express lanes with no exits then a second level with exits for local traffic all capped! Sort of a double layer tunnel.

For years, Pennsylvania, the city of Philadelphia, and the DOT have tossed around ideas of double-decking I-76 between downtown Philly and I-476 along the Schuylkill River (the section known as the Scuylkill Expressway). It's one of the oldest sections of freeway in the US, being designed in the late '40s and built in the early '50s...and a lot of it hasn't changed much since then, mainly because of geographical constraints that prevent widening (cliffs leading to the river on one side, busy freight railways on the other). The only viable option to widen it is to make it double-decked, but that isn't palatable because of the immense cost as well as the impracticality of shutting down the main freeway leading out of Philadelphia to the west for the multi-year project to be completed. Sections of the road are quasi-double-decked, with the highway running below surface streets along the riverfront near 30th Street Station, but they were built as such. 

Unfortunately, I doubt that double-decking will happen in Nashville, for basically the same reasons. The only realistic scenario I can think of is a truck restriction on routes through downtown, forcing through truck traffic to 440 and Briley Parkway, with major re-building of the western 440/40 interchange and the nightmare that is the 440/40/24 interchange. Another alternate that would encourage traffic away from downtown would be a toll for through traffic...though Tennesseans' utter disgust at the idea of paying tolls will probably prevent that from ever happening!

[PruneTracy]

1 hour ago, Nathan_in_DC said:

Interesting article by The Atlantic today on how blame for dangerous conditions on roadways has been unfairly placed almost entirely on drivers. The article argues that car manufacturers have deflected any blame for danger from the "bigger, taller" SUV and pickup arms race, while poor road designs that all but guarantee dangerous conditions continue to plague urban and rural areas alike. I do wish that there was more discussion of the poor state of driver training in the US, the mishmash of rules, and ineffective enforcement that is hobbled by pro-driving lobbies keeping effective tools from being utilized, but overall a very interesting read.

I'm obviously biased, but I'm not sure I buy the premise of the article. I used to spend a lot of time reviewing crash reports for TDOT road safety audits (the existence of which may be a point against it in the first place) and the majority of crashes of all severities happen in daytime during dry, sunny conditions. This isn't to say that the ones that occur at night and/or during adverse conditions don't count (they are often triggers for the aforementioned road safety audits) but if you want to do a sniff test on the 94% driver error rate a good place to start is that about 65% to 70% of crashes occur in good lighting with no adverse weather conditions.

And I'd say the 94% figure is on the low side. Far and away the two largest causes of crashes at least on Tennessee roadways that are HSIP-eligible are:

1. Drivers with their nose in their phone. This shows up even through the traffic cop filter in the crash report narrative. You did not get a leg cramp, your brakes did not suddenly fail, you did not see a UFO. You were looking at your phone and you don't want to tell the police officer that.
2. Ambiguity in driving behavior especially on busy multilane roads, such as:
   1. Leaving a gap in traffic queued at a signal for drivers to turn left into a corner gas station or similar. DO NOT wave at these people to go.  They will immediately make the turn without looking for other cars then get T-boned by the guy in the right turn lane who did not stop and blame you because you waved at them to go.
   2. Pulling into a two-way left-turn lane from a side road or driveway to merge into traffic. This is legal but requires a level of attentiveness apparently beyond the average driver.
   3. Cruising down the two-way left-turn lane for eight miles to skip the queued vehicles. This is not legal so not sure it should count here but is definitely driver error.

These two reasons are probably 90% on their own and most of the rest (including many severe crashes) are excessive speed and/or drunk driving. Also following too closely but I would grant that could be considered a driver education and/or enforcement issue.

[Nathan_in_DC]

12 minutes ago, PruneTracy said:

I'm obviously biased, but I'm not sure I buy the premise of the article. I used to spend a lot of time reviewing crash reports for TDOT road safety audits (the existence of which may be a point against it in the first place) and the majority of crashes of all severities happen in daytime during dry, sunny conditions. This isn't to say that the ones that occur at night and/or during adverse conditions don't count (they are often triggers for the aforementioned road safety audits) but if you want to do a sniff test on the 94% driver error rate a good place to start is that about 65% to 70% of crashes occur in good lighting with no adverse weather conditions.

And I'd say the 94% figure is on the low side. Far and away the two largest causes of crashes at least on Tennessee roadways that are HSIP-eligible are:

1. Drivers with their nose in their phone. This shows up even through the traffic cop filter in the crash report narrative. You did not get a leg cramp, your brakes did not suddenly fail, you did not see a UFO. You were looking at your phone and you don't want to tell the police officer that.
2. Ambiguity in driving behavior especially on busy multilane roads, such as:
   1. Leaving a gap in traffic queued at a signal for drivers to turn left into a corner gas station or similar. DO NOT wave at these people to go.  They will immediately make the turn without looking for other cars then get T-boned by the guy in the right turn lane who did not stop and blame you because you waved at them to go.
   2. Pulling into a two-way left-turn lane from a side road or driveway to merge into traffic. This is legal but requires a level of attentiveness apparently beyond the average driver.
   3. Cruising down the two-way left-turn lane for eight miles to skip the queued vehicles. This is not legal so not sure it should count here but is definitely driver error.

These two reasons are probably 90% on their own and most of the rest (including many severe crashes) are excessive speed and/or drunk driving. Also following too closely but I would grant that could be considered a driver education and/or enforcement issue.

Those are all good points, and I am not really sure where I place the blame, though I think there's enough to spread around! I *do* think that the way we have designed our road system has not helped, though. For so long in the minds of many, safer roads meant roads with the removal of any obstacle to higher speeds, but without the requisite restrictions and training that create good driving habits. We're seeing a reverse on that now, with road diets and traffic calming measures being put into place, but the average driver was raised on the idea that the car is in charge and anything else is a guest on the pavement, an idea that was encouraged by the development of the US road network over the last 80 years. 

When I was living in England, I was struck by how the fatalities-per-miles-driven was so much lower than it is in the US. I forget the exact numbers offhand, but it is rather startling, especially when you realize that speed limits are higher, populations are denser, and roads are "worse."  The road I would commute to work on was mostly a 60mph speed limit, but was narrow, very curvy, and with lots of blind corners... no one would go the speed limit except through the occasional straightaway, because it was madness to do so. When you went into a village, there were almost always narrowed lanes, severely restricted speed limits (20-30 in most cases) sometimes with chicanes or speed bumps, and speed displays that would tell you how fast you were going. Not to mention cars are overall smaller...my old Subaru Forester was a giant compared to many other vehicles on the road.

The fact that the driving age is 18, rigorous driver training is a requirement, and it's quite easy to lose the privilege, and roads that by and large force you to pay attention, combine to make everything safer.

Also, I'm all about leaving speeding and red-light enforcement up to cameras, freeing highway police to do more enforcement of things like illegal turns, tailgating, lane hogging, and distracted driving!

[Nashvillain]

44 minutes ago, PruneTracy said:

I'm obviously biased, but I'm not sure I buy the premise of the article. I used to spend a lot of time reviewing crash reports for TDOT road safety audits (the existence of which may be a point against it in the first place) and the majority of crashes of all severities happen in daytime during dry, sunny conditions. This isn't to say that the ones that occur at night and/or during adverse conditions don't count (they are often triggers for the aforementioned road safety audits) but if you want to do a sniff test on the 94% driver error rate a good place to start is that about 65% to 70% of crashes occur in good lighting with no adverse weather conditions.

And I'd say the 94% figure is on the low side. Far and away the two largest causes of crashes at least on Tennessee roadways that are HSIP-eligible are:

1. Drivers with their nose in their phone. This shows up even through the traffic cop filter in the crash report narrative. You did not get a leg cramp, your brakes did not suddenly fail, you did not see a UFO. You were looking at your phone and you don't want to tell the police officer that.
2. Ambiguity in driving behavior especially on busy multilane roads, such as:
   1. Leaving a gap in traffic queued at a signal for drivers to turn left into a corner gas station or similar. DO NOT wave at these people to go.  They will immediately make the turn without looking for other cars then get T-boned by the guy in the right turn lane who did not stop and blame you because you waved at them to go.
   2. Pulling into a two-way left-turn lane from a side road or driveway to merge into traffic. This is legal but requires a level of attentiveness apparently beyond the average driver.
   3. Cruising down the two-way left-turn lane for eight miles to skip the queued vehicles. This is not legal so not sure it should count here but is definitely driver error.

These two reasons are probably 90% on their own and most of the rest (including many severe crashes) are excessive speed and/or drunk driving. Also following too closely but I would grant that could be considered a driver education and/or enforcement issue.

I think the foggy conditions scenario outlined in the article was unnecessary. The part about the driver not slowing down because the shape of the road remained the same but the speed limit dropped is the key point. Drivers will drive as fast as they feel comfortable based on the width of the lane and perception about potential obstacles regardless of the posted speed limit.  I commute everyday down Clarksville pike across the bridge over the Cumberland River. The posted speed limit is 40, but it's a 6-lane road with wide lanes. Nobody drives 40. Same with the 40 mph limit through Metro Center. I'm sure most of you can come up with similar examples in your own neck of the woods.

The easiest way to get drivers to slow down and pay more attention is to narrow the roadway and add more potential points of conflict, i.e. pedestrians and other modes of transportation that have equal access to the environment. This may seem counter intuitive but most drivers don't want to kill or injure anyone and will slow down and pay attention when they realize that they aren't the sole users of the roadway.

[PillowTalk4]

I think the same questions about how many people would use a rail system came up when Atlanta built Marta decades ago.  But, imagine had they not.  And, Marta is not the best rail systems compared to other cities in my opinion.   People in Nashville will have to grow into using a rail system that is without question.  But you don't build a rail system for the short term.  You build it for the long haul.  I can't remotely imagine the DC, MD, VA area without the Metro System.  And, while some say it is underutilized, it is still being expanded.  Simply because they cannot continue to expand roads in the region.  Will it ever eliminate people from commuting by car?  Of course not.  But it takes on average about 620,000 people off the roads every week day.  Trust me, if the DC area didn't have that option, traffic would be even more horrendous.  And, yes, the traffic here is horrendous.  When they've had to shut down  just one of the lines for major repairs and or upgrades, you could really feel the impact of those closures.  

I'm not sure why the suburbs would need to be walkable for a rail system to work.  As with most rail systems you build stops that have commuter parking lots/garages.  The stops in the core do not need parking typically.  So,  it diminishes the need to drive into the core and reduces the amount of time people spend in their cars getting into the core.  I'm fortunate in that I live and work in the suburbs, so I do not use the metro system regularly.  But, when  I lived in VA, I lived about 2 miles away from a metro station.  The complex I used to live in provided a shuttle to that stop throughout the day.  If I needed to go to the airport or into the city I could hop on that shuttle, go to the metro station, hop a train to the airport or into DC.  Depending on where I got off in DC, I could walk to where I wanted to go, catch another train, hop a cab or Uber.  My partner could  go from the metro stop in our neighborhood directly to the Pentagon where he works.  When we moved from VA into MD, he then had to drive to a metro stop (about 3-4 miles), park his car there all day and then take two trains to get to the Pentagon.  It is far faster than him driving to the Pentagon each day and less stressful.  If he really wanted to he could catch a bus to the Metro Station.  But, the bus routes are about a mile from our home and it would add more time to his overall commute time.  All I know is, when he drives to work, he has to decompress a lot more when he gets home than when he takes the train.  

I can't begin to project the cost of building a rail system in Nashville or project how many people with use it.  Chances are if one is ever built it may take decades to see a cost benefit if any.  But what is the cost to not doing anything but allowing a bad situation to worsen?  While the CBD is becoming more of work and play environment, the great majority of the workers in the CBD probably will never live in downtown or midtown.  Affordability will prevent that.  Additionally a lot of people will not want to raise a family in downtown.  So, Nashville will still have to address mass transit in a way that is efficient and easy to use.  Busing alone is not the answer.  If Nashville continues to grow at the pace it is projected to, then quality of life and work productivity is going to be heavily impacted by traffic congestion in Nashville more so than it already is today.

[FluffyP13]

I’m pretty sure someone threw out the idea of double decking the interstate system a few years ago when the big public transit/subway tunnel thing was up for vote w mayor Barry. There might have been a rendering too? Can’t remember.


Sent from my iPhone using Tapatalk

[chris holman]

 

[Nash_12South]

I totally agree we would eventually use a mass transit system that includes above/below ground rail. I just wonder how, given where we are now, do we get there. We would have to be in partnership with our surrounding counties. We would have to have state government supporting our efforts. I'll admit ignorance as to what decision makers are actively working on any wide ranging plan. Which statewide elected officials are working toward this effort? All the ideas presented are great, but who do we look toward to spearhead this vision? Our current mayor? Who is saying they will run for mayor and supports building a rail system asap? I'm not comfortable being anti-car, anti-driving, anti-road widening, until I see a mass transit plan done and under construction.

Edited December 1, 2021 by Nash_12South

[Nathan_in_DC]

18 hours ago, Nashvillain said:

I think the foggy conditions scenario outlined in the article was unnecessary. The part about the driver not slowing down because the shape of the road remained the same but the speed limit dropped is the key point. Drivers will drive as fast as they feel comfortable based on the width of the lane and perception about potential obstacles regardless of the posted speed limit.  I commute everyday down Clarksville pike across the bridge over the Cumberland River. The posted speed limit is 40, but it's a 6-lane road with wide lanes. Nobody drives 40. Same with the 40 mph limit through Metro Center. I'm sure most of you can come up with similar examples in your own neck of the woods.

The easiest way to get drivers to slow down and pay more attention is to narrow the roadway and add more potential points of conflict, i.e. pedestrians and other modes of transportation that have equal access to the environment. This may seem counter intuitive but most drivers don't want to kill or injure anyone and will slow down and pay attention when they realize that they aren't the sole users of the roadway.

In London, in some of the busier pedestrian neighborhoods, they have started doing some traffic integration measures instead of just traffic calming. I believe it's in Kensington where they have completely removed curbs and only placed minimal street markings on a few roads...and vehicle/pedestrian incidents have gone down drastically. Drivers are forced to pay attention to what's around them, because there are pedestrians and cyclists sharing the street. And likewise, pedestrians are forced to pay attention to what's happening around them as well. People tend to walk where sidewalks once were, and cars stick to the marked driving area, but the separation isn't a hard curb (kerb, I guess in this situation), rather it's planters, bike racks, street lights, and other interspersed physical barriers. 

[PaulChinetti]

21 minutes ago, Nathan_in_DC said:

In London, in some of the busier pedestrian neighborhoods, they have started doing some traffic integration measures instead of just traffic calming. I believe it's in Kensington where they have completely removed curbs and only placed minimal street markings on a few roads...and vehicle/pedestrian incidents have gone down drastically. Drivers are forced to pay attention to what's around them, because there are pedestrians and cyclists sharing the street. And likewise, pedestrians are forced to pay attention to what's happening around them as well. People tend to walk where sidewalks once were, and cars stick to the marked driving area, but the separation isn't a hard curb (kerb, I guess in this situation), rather it's planters, bike racks, street lights, and other interspersed physical barriers. 

Reminds me of the old videos you see of all the pedestrians and horse drawn carriages intermingling and everyone is getting along and pay attention.

Here it is

https://www.youtube.com/watch?v=VO_1AdYRGW8

Edited December 2, 2021 by PaulChinetti

[Nathan_in_DC]

57 minutes ago, PaulChinetti said:

Reminds me of the old videos you see of all the pedestrians and horse drawn carriages intermingling and everyone is getting along and pay attention.

Here it is

https://www.youtube.com/watch?v=VO_1AdYRGW8

One of the many nefarious acts of auto makers in the 20th century was the wholesale creation of the idea of jaywalking in order to make roads primarily for car usage, thereby enabling the sale of more cars. https://www.vox.com/2015/1/15/7551873/jaywalking-history

[chris holman]

Interesting video on transit in America  cities.

"Why American public transit is so bad is the title."
 

Edited December 6, 2021 by chris holman

[rolly]

America's 17th largest city versus Canada;s largest? 

[MontanaGuy]

On 12/5/2021 at 7:02 PM, chris holman said:

Interesting video on transit in America  cities.

"Why American public transit is so bad is the title."

That was an excellent and informative video.  It lays out the problems very clearly.  At one time in our history it probably made sense to funnel all of the transit to a central downtown core because that's where the majority of workers commuted to everyday but businesses often can't afford the high costs of downtown offices just like their workers who can't afford to live there so the cheaper costs of office parks in suburbs became more prevalent.  I realize it's a logistical nightmare to create an efficient mass transit system but we should definitely be looking at cities in other countries where they're doing a good job of it!

[chris holman]

Some history 

The streetcars were bought  out by the auto industry.

[AsianintheNations]

Probably not terribly exciting to many, but there appears to be work on the I-40W Exit 201 ramp, presumably a formal widening to two lanes (I hope). This was one of the interchanges highlighted for improvement in the I-40/I-81 corridor study (https://www.tn.gov/content/dam/tn/tdot/long-range-planning/studies/i-40-81-study/I-40-81-Round2-Region3-presentation.pdf .) In practice, it's already usually an informal two-lane ramp, with left-turn cars queuing halfway in the left shoulder and right-turn cars queuing halfway into the right shoulder (except when someone doesn't get the memo and drives down the middle), so hopefully they've recognized that that is a much more efficient arrangement. With all the new apartments on Charlotte and Cabot, this would help alleviate the ramp congestion a little bit if extended all the way to the actual highway exit.

In the vicinity, there have also been seemingly a lot of accidents recently between exits 201 and 204, including a 12-car pile-up that started with a dump truck and school bus collision, which resulted in the entirety of I-40W being closed for a few hours during rush hour (fortunately no one died). There was another accident in the same spot the very next day, but it only closed one lane. I'm not sure what it is about that area ... maybe the lane merge from Briley being overly long to the point where people get tricked into thinking it is a permanent lane, only to be dropped on a curved hill? But in any case, I would really like to see a visualization of accident locations as I feel that this stretch is especially problematic.

 

[smeagolsfree]

I am interested in what the Inner Loop • Collector-distributor road system through downtown is going to be!!! there is no mention of the details in the document as to what that will involve. 

Anyone with any kind of knowledge able to chime in???

[Bos2Nash]

We kinda/sorta already have it between Demonbreun and Charlotte, but please for all that is holy, please don't make it bigger! Also the notion of extending it from essentially Jefferson to Hermitage should be considered treason

I feel like one of the best ways to make this more efficient would be to vastly cut down on the access points to the highway. Doing this would almost this stretch of highway for the cap that we have all been dreaming of in the area. I'm just gonna quote the cap remarks below, but to me actually reducing the amount of access points would make this area of the city MUCH more efficient, even if it meant widening the ramps at the north and south ends

On 7/9/2021 at 5:45 PM, Bos2Nash said:

This is great forethought on planning's part. In some respect it means at least the Planning Department is think a cap could be a realistic solution to stitch the city together. To me, for a pedestrianized George L. Davis (also had no idea that was the name of this stretch) to be successful along with a highway cap, TDOT will need to be willing to give up most of the ramps in this area. There has been countless idea and studies thrown around about capping the interstates – most notably to me from the Civic Design Center #1 and #2 – but one of the greatest successes of Boston's Big Dig is the improvement of Atlantic Ave and Purchase St that straddle the Rose Kennedy Greenway and one of the reasons it is so successful is because of the lack of interruption from vehicles. Giving up 8 (EIGHT!!) on/off ramps within this area, and keeping the surface roads at two or three lanes (three lanes at most even with turn lanes) could really spur a successful area. 

[smeagolsfree]

I am unsure how all of this would work and if there is even room to expand the existing bottleneck to an even bigger bottleneck.

[PruneTracy]

13 hours ago, AsianintheNations said:

Probably not terribly exciting to many, but there appears to be work on the I-40W Exit 201 ramp, presumably a formal widening to two lanes (I hope). This was one of the interchanges highlighted for improvement in the I-40/I-81 corridor study (https://www.tn.gov/content/dam/tn/tdot/long-range-planning/studies/i-40-81-study/I-40-81-Round2-Region3-presentation.pdf .) In practice, it's already usually an informal two-lane ramp, with left-turn cars queuing halfway in the left shoulder and right-turn cars queuing halfway into the right shoulder (except when someone doesn't get the memo and drives down the middle), so hopefully they've recognized that that is a much more efficient arrangement. With all the new apartments on Charlotte and Cabot, this would help alleviate the ramp congestion a little bit if extended all the way to the actual highway exit.

It's not desirable to extend all the way to the ramp diverge for traffic engineering nerd reasons but your description of the improvements are correct and should help simply from being marked (and having new pavement, as it was people were dodging potholes on the shoulder). Here is a layout of the proposed conditions.

The technical report for Charlotte Pike in this area also recommended relocating the Cabot Drive intersection to the west to coincide with the easternmost Cracker Barrel entrance. This would help separate these two signals and also keep people trying to turn left into Cracker Barrel from jamming everything up; it should also not require ROW takes for Krystal or Waffle House. This will probably be done as part of the Charlotte Pike widening from I-40 to Old Hickory Boulevard which will be constructed sometime in the 24th century.

13 hours ago, AsianintheNations said:

In the vicinity, there have also been seemingly a lot of accidents recently between exits 201 and 204, including a 12-car pile-up that started with a dump truck and school bus collision, which resulted in the entirety of I-40W being closed for a few hours during rush hour (fortunately no one died). There was another accident in the same spot the very next day, but it only closed one lane. I'm not sure what it is about that area ... maybe the lane merge from Briley being overly long to the point where people get tricked into thinking it is a permanent lane, only to be dropped on a curved hill? But in any case, I would really like to see a visualization of accident locations as I feel that this stretch is especially problematic.

In the in-progress I-40/I-81 Corridor Study, this segment didn't show up with an actual-to-critical crash rate above 1.0. For more traffic engineering nerd reasons this would suggest that the crashes in this area are within what would be expected with random variation. Of course the study also used data from 2014 to 2018 so conditions may have changed since then.

https://www.tn.gov/content/dam/tn/tdot/long-range-planning/studies/i-40-81-study/I-40-81-ExistingFutureConditionsReport.pdf

3 hours ago, smeagolsfree said:

I am interested in what the Inner Loop • Collector-distributor road system through downtown is going to be!!! there is no mention of the details in the document as to what that will involve. 

Anyone with any kind of knowledge able to chime in???

I'm not supposed to have the draft plan so I can't share pictures but the idea is that each side of I-40/I-65 through downtown would have a one-way, four-lane C-D road (also with a bike lane, sidewalk, and other hippie stuff on the outside edge). These are surface roads that would have intersections with all other surface roads crossing the Interstate from 12th Avenue to Charlotte (it would work better if it skipped 12th and started at Division but that's my interpretation of it). The C-D roads are accessed from dedicated ramps that merge/diverge outside of the I-40/I-65 concurrency (i.e., beyond the interchanges on each side). I'm not sure how this is supposed to work since the exit spacing doesn't get any better outside this area, and it would require additional flyovers at each interchange, but that's what it shows. The C-D roads allow every ramp to be eliminated on the concurrency and the Interstate could then be widened to at least four lanes in each direction with proper shoulders. The typical section shows retaining walls between the Interstate and C-D roads and if this were the case it could also be built on a smaller footprint than existing ROW, opening that space for development or other uses. Note also @Bos2Nashthis is not incompatible at all with a freeway cap, aside from having it bordered by two one-way four-lane roads. Sorry, it's one lane bigger, but it should improve traffic considerably.