Other People's Rail: Amtrak, commuter rail, rapid transit news & views outside New England

[DominusNovus]

Freeway ROW allow typically up to 6% grade. High Speed Rail usually tries to come in under 2% grade. So you are going to have many sections of the highway ROW where the grade is too steep and needs to be (massively) leveled.

Highway ROW does not equal HSR ROW.

Question: why does the rail have to follow the highway grade? It could go at a more gentle grade easily enough.

 

[F-Line to Dudley]

Question: why does the rail have to follow the highway grade? It could go at a more gentle grade easily enough.

It's a huge amount of concrete pour for sinking the gentler rail grades into retaining-walled cuts and elevations. And, when the grade difference is significant...outright MOAR TUNNEL.

The NEC FUTURE Commission did a lot of MOAR TUNNEL on its various Shoreline bypass crayon alignments along an Inland route of I-84 and the Mass Pike medians, because the highway grades were so much stiffer than the allowable rail grades. So it does lead to lots of cost blowouts in the real world.


EDIT: Don't forget as well, curve allowances hurt when you're trying to shiv an 80-160 MPH design rail line along a 65-75 MPH design highway curve. So you end up MOAR TUNNELING a lot around banking curves as well.

 

[DominusNovus]

It's a huge amount of concrete pour for sinking the gentler rail grades into retaining-walled cuts and elevations. And, when the grade difference is significant...outright MOAR TUNNEL.

The NEC FUTURE Commission did a lot of MOAR TUNNEL on its various Shoreline bypass crayon alignments along an Inland route of I-84 and the Mass Pike medians, because the highway grades were so much stiffer than the allowable rail grades. So it does lead to lots of cost blowouts in the real world.


EDIT: Don't forget as well, curve allowances hurt when you're trying to shiv an 80-160 MPH design rail line along a 65-75 MPH design highway curve. So you end up MOAR TUNNELING a lot around banking curves as well.

Why tunneling and not elevating?

 

[F-Line to Dudley]

Why tunneling and not elevating?

You can elevate. That's also a shitload of concrete for retaining walls and new overpasses, and limits to how high you can elevate when there are pre-existing road overpasses of the highway.

Incompatible grades and curves are big cost blowouts any which way...that's the point.

 

[DominusNovus]

You can elevate. That's also a shitload of concrete for retaining walls and new overpasses, and limits to how high you can elevate when there are pre-existing road overpasses of the highway.

Incompatible grades and curves are big cost blowouts any which way...that's the point.

Allow me to phrase the question this way:
Take your typical stretch of highway. Which is easier/cheaper, elevated or tunnels to smooth of the grade? Does the answer change if the highway is windy enough that track would have to cross over/under the road?

 

[F-Line to Dudley]

Allow me to phrase the question this way:
Take your typical stretch of highway. Which is easier/cheaper, elevated or tunnels to smooth of the grade? Does the answer change if the highway is windy enough that track would have to cross over/under the road?

It depends entirely on the application. The NEC FUTURE inland routing along I-84 and the Mass Pike would've had to have long tunnels through the steep hills in Tolland, CT and gone off the highway alignment through some banking curves that were mid-climb on the hills. The Pike would've required tunnels in Sturbridge-Charlton and Auburn-Millbury for sure, and required going off-alignment with flyovers/duckunders for several curves in Worcester County. That was to be a 165 MPH ROW, so the curve tolerances were especially brittle and problematic where the highways twist while on steep grades. That would've cost billions of dollars, and be complicated construction because of the glacial rubble composition of those hills.

On the Los Angeles Metrolink example, the I-10 alignment does some tricky flyover/flyunder action near Cal State L.A. at the I-10/I-710 interchange to pound out a sharp S-curve curve on the highway. That was done 30 years ago commensurate with a big highway widening project, so the costs were buried in a far larger pie but were significant despite the flat grades, relatively few curves, and lower Commuter Rail speeds.

 

[Koopzilla24]

Helpful tool for highway gradients HERE

 

[Stlin]

Not a serious transport development in any way, but sort of fun; Out in the bay area, BART today announced a series of new anime mascots. Apparently reasonably well received, but admittedly BART is also suffering from reliability issues of their own so some apparently see it as a bit of a panacea, but I would love to see the MBTA also do *something* to liven up it's image in the near future.

Since COVID, BART's rider demographics have changed considerably. It's gotten much younger, more diverse in race and less likely to own a car. We are working to meet them where the young riders -- especially Gen Z -- are and speak their language, even if it is kind of weird.

https://twitter.com/i/web/status/1662259308438999040

Anime Mascots | bart.gov

BART is excited to announce the release of five BART- and Bay Area-themed anime mascots that will help us in our mission to promote public transportation use, especially among youth riders -- a growing and reliable ridership demographic. Inspired by BART frontline employees and BART-contracted...

www.bart.gov

 

[Arenacale]

That PR department better get ready for when those are Rule 34'd...

 

[HenryAlan]

BART has a consistently good social media presence. That definitely doesn't make the service better per se, but does help quite a bit with engagement and overall communication effectiveness.