Jump to content

The Transportation and Mass Transit Megathread


TopTenn

Recommended Posts

I agree that an overhaul of the overpasses and laying new track within the ROW is probably the only way to get additional rail on the lines. We would never see heavy rail (which to me is a third rail powered train) within this close proximity of the CSX freight lines (at least without additional separation protection), but a regional rail type setup (ie WeGo Star) could slip into the ROW with the improvements Baronakim is laying out. Ideally the regional rail would be EMU powered locomotives, but this would required electrification of the service which is a bullet that I don't think anyone would want to touch.

An overall of rail and highway is a necessity for our city's continued success. And ultimately it may come with the price tag of Boston's Big Dig. The Big Dig was originally planned all the way back in the early 80's (yes actually way back then) with an original price tag of around $14 million (which after design later in the decade shifted to $2.8 billion), by the time that the state got through EIRs in the 80s and pulled the trigger on construction in the 90's and finished construction, that cost ballooned to $14.5 billion! The received $7 billion in aid from the federal government and borrowed the rest. After factoring in interest and transit commitments, that final cost is at $24.3 billion!! The state of Massachusetts will be paying the debt until 2038. Here is an interesting article about breaking down a very complex project.

All this being said, what Nashville is looking at with its rail, roads and infrastructure is going to be even more daunting very quickly. We have a very limited amount of tax revenue (compared to the states) and a political viewpoint that clearly illustrates they don't want to invest in these things. I think we are very quickly approaching a tipping point...

  • Like 3
Link to comment
Share on other sites


4 hours ago, Bos2Nash said:

I agree that an overhaul of the overpasses and laying new track within the ROW is probably the only way to get additional rail on the lines. We would never see heavy rail (which to me is a third rail powered train) within this close proximity of the CSX freight lines (at least without additional separation protection), but a regional rail type setup (ie WeGo Star) could slip into the ROW with the improvements Baronakim is laying out. Ideally the regional rail would be EMU powered locomotives, but this would required electrification of the service which is a bullet that I don't think anyone would want to touch.

An overall of rail and highway is a necessity for our city's continued success. And ultimately it may come with the price tag of Boston's Big Dig. The Big Dig was originally planned all the way back in the early 80's (yes actually way back then) with an original price tag of around $14 million (which after design later in the decade shifted to $2.8 billion), by the time that the state got through EIRs in the 80s and pulled the trigger on construction in the 90's and finished construction, that cost ballooned to $14.5 billion! The received $7 billion in aid from the federal government and borrowed the rest. After factoring in interest and transit commitments, that final cost is at $24.3 billion!! The state of Massachusetts will be paying the debt until 2038. Here is an interesting article about breaking down a very complex project.

All this being said, what Nashville is looking at with its rail, roads and infrastructure is going to be even more daunting very quickly. We have a very limited amount of tax revenue (compared to the states) and a political viewpoint that clearly illustrates they don't want to invest in these things. I think we are very quickly approaching a tipping point...

Hold on... the original cost estimate for The Big Dig was only $14 million?  I mean I know it's only an estimate and projects like that commonly compound in price as it actually comes to fruition and work moves forward, but that just seems like a comically horrendous estimate!  1980 was awhile ago, but it's not like inflation would change the equation to that extent.  $14 million is the sort of cost estimate I would expect to see for project on that scale if it were done in like 1750.  :rofl:

Edited by BnaBreaker
  • Like 3
Link to comment
Share on other sites

52 minutes ago, BnaBreaker said:

Hold on... the original cost estimate for The Big Dig was only $14 million?  I mean I know it's only an estimate and projects like that commonly compound in price as it actually comes to fruition and work moves forward, but that just seems like a comically horrendous estimate!  1980 was awhile ago, but it's not like inflation would change the equation to that extent.  $14 million is the sort of cost estimate I would expect to see for project on that scale if it were done in like 1750.  :rofl:

That was a figure I remember hearing years ago at least. That may have been a political pitch price tag (as I cant find anything lower than the 2.5/2.8 billion estimate). 

The mega-project has spurred countless "best-practice" articles, but this one I just found specifically looks at the cost estimate and its inflation.

https://www.pmi.org/learning/library/practices-mega-project-cost-estimating-6668

  • Like 1
Link to comment
Share on other sites

I love daydreaming like this. Nashville needs one of two things to make big rail (light or heavy): development density along corridors or a park and ride culture. Worsening congestion could help fuel the latter but it’ll take some “years ahead” planning to zone, incentivize, and build real transit oriented development, both in Davidson and surrounding counties.

Right now and in the next five to eight years, I think that really only downtown, midtown, an airport connector, and maybe Murfreesboro and Gallatin Pikes have the density and ridership to support rail. But once it proves successful, I think there will be appetite to continue expansion (billions of dollars and decades after it is truly needed).

 

  • Like 2
Link to comment
Share on other sites

1 hour ago, rookzie said:

Pardon me for coming out of thin air.

As far as the railroad swing bridge is concerned, there's simply no way feasible that it can me made to accommodate anything other than CSX freights, Amtrak  passenger rail, and possibly railroad-type FRA-compliant (Federal Railway Admin) commuter rail, such that of the WEGO Star.

FRA-compliant commuter rail volume still might need a dedicated bridge, due to the fact that the existing swing bridge through-trusses were built only wide enough to accommodate a single track.  So naturally it's a bottleneck, even for freights ─ a scenario I have observed as a daily norm based on CSX logistics along its entire network east of the Miss. River.  Sadly, the original owner of that bridge ─ the Louisville & Nashville RR ─ elected to build the span as single track, as with most of its other bridges in parts of the South.  Trains often are held stopped on either side of the bridge for opposite movements to clear.  The only way to build a fixed span bridge dedicated for FRA-compliant commuter rail, would be to construct long approaches to either end of the bridge, since such equipment generally cannot run along steep grades required for an ascent to the fixed span with required navigational towing clearance.   The approaches to a fixed-span bridge would have to be quite lengthy ─ probably an improbably surmountable hurdle of approval more than the physical bridge height itself, given that the western approach would have to be built in the downtown area.  The state legislature might even fight such a plan.

Swing bridges are generally obsolete, because they often pose as navigational hazards ─ as the U.S. Coast Guard will be the first to exclaim ─ because their center (pivot) pier reduces the effective width of a shipping channel to less than one-half the distance between the inner piers of the fixed bridge spans.  What could be one large wide shipping channel has to be made into two separate channels, on either side of the open swing span, the width of which itself takes reduces navigational lateral clearance.  Swing bridges also are the slowest in mechanical operation.

The only feasible type of bridge that could serve FRA-compliant commuter rail would likely would have to be a movable-span bridge ─ most likely a vertical-lift bridge ─ with two end towers to hoist the movable span vertically.  Since the early 1980s, only two such bridges remain in the entire state ─ one between McEwen and New Johnsonville, and one at Chickamauga ─ both spanning the Tennessee River.  Vertical-lifts are more common along intra-coastal areas (NY, NJ, VA, FL, WA, OR, CA), as well as over rivers near the Great Lakes (Duluth, Chicago, Cleveland,...) and the Gulf region (LA, TX).  A few can be spotted inland, as with the two in TN.  While vertical-lift bridges provide the most height and width in navigational clearance, one the biggest issue is that they require towers, the appearance of which often is objectionable, particularly to naysayers in public office.  A second issue is cost, as they have more complex machinery with also requires more maintenance.  New vertical-lift bridges have been built during recent decades, often to replace severely deteriorated swing bridges and bascule leaf ("jackknife)" bridges, but new swing bridges just are no longer constructed anymore, as far as I'm aware.

Now as far as heavy-rail transit (subway/metro-like equipment with power 3rd-rail) and light-rail are concerned, a fixed bridge indeed would be more feasible and could be built more amenable to the landscape of downtown.  Two examples of such bridges for light rail and heavy-rail are the Tilikum Crossing (Portland, OR) ─ for bus, cyclists, pedestrians, and emergency vehicles only, with light rail ─ and the Skybridge (Vancouver, BC CAN), dedicated for the Translink Skytrain.  These bridges were built with a slightly arched deck, which can be easily negotiated by the types of trains that traverse them.  They're no good for freights or FRA-compliant commuter rail.  The only exception might be with electrified self-propelled equipment, such as with Chicago's Metra Electric, Northern Indiana's line Chicago to South Bend, Denver's RTD A-Line, and (some of) Philly's SEPTA Regional rail.  Such equipment could serve and has been in such service along grades not readily handled by locomotive-hauled trains.

As I see it, the swing bridge just cant be used for commuter rail coexisting with CSX freights ─ nor do I see it as being capable of being modified for such.  Even replacement with a new center (swing) span would not be feasible, given the condition and size and condition of the pivot pier, and the pivoting machinery, and the pier would have to be strengthened and enlarged in place.   Also, it would be a bit tricky to build a bridge of any kind parallel and close to the swing bridge, which must remain operable at anytime.  Any new bridge would have to be erected at a point at least the distance from the center span to the *dolphin* ─ that cylindrical steel-piling structure filled with concrete and positioned upstream of the bridge ─ the purpose of which is to minimize the chance of allision against the center pier by a towing movement (barges).  That alone presents yet another problem.   All new double-tracked spans *could* be pre-fab'd and floated to the site for replacement, so that would be no big issue, and some monetary deal to cover lost revenue and operating expenses would need to be worked out with CSX to persuade it to reroute traffic into and from CSX Nashville Terminal through the Radnor Yard and the Radnor Cutoff bridge (Shelby Bottoms) through East Nashville to bypass the site temporarily.  The Cutoff trestle and bridge also is a single track bridge, so some traffic would have to be bypassed with other means and routes systemwide, away from the region entirely.  But with all that trouble, it still would be best in the long run to build a new vertical-lift bridge at the site ─ again, possibly a political issue at stake, even if funding could be garnered to entice CSX. 

A few years in the past, I mentioned the need of some dedicated transit bridge somehow connecting the west bank to the east side.  With no coordination and collaborative efforts among all stakeholders (Metro, Oracle, ...), there seems little chance of taking advantage of opportune timing of proposals.  I do recall that the now long-stillborn Maytown proposal was stipulated to require a bridge dedicated to transit.

As a point of clarification, one of the lift bridges you reference is located at New Johnsonville where highway 70 crosses the Tennessee River/Kentucky Lake.

(I have family nearby and see that rusty old bridge frequently.)

photo and google map images from bridgehunters.com

2885BD99-6FDD-4DCB-B50F-FBD2B33B3C0D.jpeg

95710EFC-9285-4E56-A049-2812808B1CF6.jpeg

  • Like 2
Link to comment
Share on other sites

If it’s quicker I think truckers would take it. If not then no. I guess too if they could see a traffic jam ahead they could bail off too. 

I’m thinking of the warehouse that sits up on the hill by the 24/65 split. Trucks will still be coming and going into town. I wonder if it would be a noticeable difference? 

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

12 hours ago, PaulChinetti said:

If it’s quicker I think truckers would take it. If not then no. I guess too if they could see a traffic jam ahead they could bail off too. 

I’m thinking of the warehouse that sits up on the hill by the 24/65 split. Trucks will still be coming and going into town. I wonder if it would be a noticeable difference? 

We would absolutely still see local truck traffic but the long haul stuff would likely route around the city during rush hours. It would make a difference - for a while. But I think a completed 840 circle would really spur a lot of development on the Cheatham / Montgomery / Robertson corner of greater Nashville metro.

  • Like 4
Link to comment
Share on other sites

Give Yourselves A Really Really Big Clap Round Of Applause GIF - Give  Yourselves A Really Really Big Clap Round Of Applause Appreciative -  Discover & Share GIFs

Way to go WeGo. Only 15 years after the same technology was introduced for the MBTA (Boston) and almost 20 years after the MetroCard (NYC, which is being replaced now).

I understand that we are much smaller than those two examples, but hot damn the technology ain't that foreign. WeGo prolly just had to save up for the last 10 years or so for the technology because our city and state either cant afford to or refuses to invest in transportation technology (other than single occupant vehicles of course)

  • Like 4
Link to comment
Share on other sites

3 hours ago, Bos2Nash said:

Way to go WeGo. Only 15 years after the same technology was introduced for the MBTA (Boston) and almost 20 years after the MetroCard (NYC, which is being replaced now).

We're very slow to the party. Possibly in related news, the senior advisor for transportation and infrastructure is leaving her position, per the attached article. I noted from Mayor Cooper's quotes around her accomplishments - the words "plan, strategy, and hope" used throughout. She got some grant money, established a department, and some other stuff - but in no way got the needle moving to where it needs to go (IMO). C'mon Nashville, let's get GOING.

https://fox17.com/news/local/senior-adviser-to-nashville-mayor-on-transportation-to-resign

  • Like 1
  • Sad 1
Link to comment
Share on other sites

28 minutes ago, Flatrock said:

We're very slow to the party. Possibly in related news, the senior advisor for transportation and infrastructure is leaving her position, per the attached article. I noted from Mayor Cooper's quotes around her accomplishments - the words "plan, strategy, and hope" used throughout. She got some grant money, established a department, and some other stuff - but in no way got the needle moving to where it needs to go (IMO). C'mon Nashville, let's get GOING.

https://fox17.com/news/local/senior-adviser-to-nashville-mayor-on-transportation-to-resign

Mayor Coopers revolving door just keeps spinning. 

  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site you agree to our Terms of Use and Privacy Policy. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.