Tram Trains
48 comments
·July 23, 2025PLenz
f_allwein
We have this in Karlsruhe, Germany: https://en.m.wikipedia.org/wiki/Karlsruhe_Stadtbahn
woodpanel
The article mentions the old chestnut „but due to preference given to automobiles“ without further explaining what that actually means. Since there’s no need to. We’re all very well aware how to fill out the blanks in our minds: cars are bad, car manufacturers are evil, they did this to us, only government intervention can save us.
yet, what this historiography conveniently omits is that it was the glorious government intervention that strangled the often privately owned interurban/tram/train companies out of business due to massive amounts of roads being built under public works programs that were all too common from the 1920s-1940s.
As the article mentions later:
automobile doomed the interurban whose private, tax-paying tracks could never compete with the highways that a generous government provided for the motorist.
that provision had many names, one was “New Deal”
I don’t have a solution but two observations:
1) somehow in Asia never happened what happened in the West, that is, private transportation companies are still private, they prosper, and the societies excel at mobility.
2) Never ever destroy built infrastructure. Always plan for the possibility for a comeback. Post-war, many cities removed tram tracks. But even a rusty tram track is cheaper to repair 70 years later than, paying upfront for the dismantling and 70 years later for a complete new construction.
mauvehaus
There are real costs to retaining disused tram tracks. In Boston, the MBTA Green line E branch tracks were left in place for decades after service was discontinued, no doubt increasing costs every time they had to pave around them or do utility maintenance below them.
In Somerville, the Somerville Community Path was a disused heavy rail right-of-way when I first visited in 2002 or 2003. Ripping up the tracks and putting in the community path improved walkability to a Red Line station (Davis) and creating a nice space for recreational walking and cycling.
There are real trade offs to leaving disused infrastructure in place. Not losing a continuous right-of-way is a huge upside, but there are definitely downsides too.
nocoiner
I really like your point #2. A little bit of me dies every time I see a rail-to-trail project. Granted, many (most? all?) of those lines have approximately a 0% chance of ever being economic again, but there’s also rail-centered redevelopment that’s being permanently foreclosed.
bell-cot
Over the longer haul, 99% of the potential infrastructure value of the "destroyed" rail line is in the unified right of way ownership. Rails rust (or are sold for scrap, legally or not), ties rot, ballast (gravel) becomes choked with dirt, brush, and trees, and bridges and viaducts crumble. So long as the rail-to-trail project doesn't erect a too-high legal barrier to eventual higher-value uses, it's actually a best case scenario.
toast0
Tram tracks are a triping and cycling hazard. Leaving unused, presumably unmaintained tracks in your city for 70 years just in case has a cost.
Keeping unused right of ways open is challenging too. Adjacent properties will tend to encroach, and depending on specifics and local rules, may be able to claim the encroached property through adverse possession.
kposehn
> The low density of Charlotte means a transport network like Munich’s is not viable, but the city could take its pre-existing light rail network and join it up to the extensive network of railroad lines around the city that are currently used only for moving freight.
This is not a feasible option due to the vast difference in crashworthiness standards between US freight rail and other system types such as light rail. The FRA actually prohibits allowing these two types on the same network of tracks at the same time. However, they could use a line along the right-of-way were it big enough to accommodate another set of tracks.
bobthepanda
This actually changed fairly recently in 2018 and European rolling stock, including tram trains are allowed under alternative compliance regulations.
Older American regulations favor pure buff strength. European regulations tend to emphasize making collisions impossible by using signalling and automatic emergency stop braking, and then crumple zones and other safety technologies. And the US has ended up adopting similar signalling regulations anyways with PTC, so now it is perfectly fine to allow European rolling stock. We already emphasize safety technologies over buff strength in US car regulations.
https://railroads.dot.gov/regulations/federal-register-docum...
desas
Is there a reason you couldn't build new light rail trains to a higher level of crashworthiness than they are currently? I don't know the full details, but that's how tram-trains in Sheffield, UK were allowed access to the main railway network.
kposehn
Unfortunately no. The main difference is mass - US trains are vastly heavier than anything in the UK so by the time you make a tram crashworthy it isn't a tram any longer.
That said, I believe the FRA did allow lighter designs such as the Siemens FLIRT for commuter lines so the rules are definitely less onerous.
persolb
It’s done in various places. NJ Riverline is an example. There are a bunch of others.
The bigger problem is the freights just have no interest in sharing the tracks with passenger trains, and requiring heavier and more expensive passenger trains is a convenient way to price the project to death.
MisterTea
How does this work for say, the New York and Atlantic Railway which runs freight trains on the same tracks as the Long Island Rail Road? There are stations where a freight train passes through while a passenger train is behind it.
bombcar
Does the locomotive weigh half a million pounds and have no passengers? Then it’s heavy rail.
bell-cot
In quite a few cases, old rail right-of-ways near cities are large enough for an extra track or few. Because, back in the heyday of American railroads, they either had another track or few, or they expected to.
The biggest issue is often bridges. Retaining the land that additional track(s) were on is fairly cheap. Building and maintaining rail bridges is not.
And building the light rail bridges for a transit system is not cheap. It's just less horribly expensive than building bridges which you could run strings of 220-ton freight locomotives over.
jazzyjackson
Funny reason there used to be double tracks almost everywhere that is now single tracked: while the government granted the property to the railroads, they still excised a tax over the portion of that land used by the railroads, so in the 70s when companies were going bankrupt left and right they tore up their own infrastructure to reduce the tax burden. Hell of a fuckup.
bell-cot
Not exactly...
To really be usable - by revenue-generating trains - track has to receive regular maintenance. Which costs money. If your RR is desperately short on both revenue-generating trains and money, then it's kinda obvious that you cut the no-longer-necessary expenses.
And railroad rails are steel, generally weighing 100+ pounds per yard. Scrap steel sold for far fewer dollars per ton in the '70's - but you get about 200 tons per mile of unused track that you tear up.
Animats
London? London has 13 major railroad stations and they're all dead ends.[1] Crossrail, with expensive tunnels, now provides some east-west through services.
[1] https://en.m.wikipedia.org/wiki/File:Major_railway_stations_...
zimpenfish
Pretty sure London Bridge has through trains (Thameslink) and also Blackfriars.
e.g. today's 18:24 from Horsham to Peterbrough going through London Bridge at 19:31, Blackfriars at 19:37 and then St Pancras (for a triple!) at 19:46 https://www.thetrainline.com/live/departures/london-blackfri...
Animats
There's a fan-out at London Bridge to three more stations, but everything dead-ends within 2km or so. You can't continue west or north and get out of London on any of those tracks.
lpribis
Yeah the only through-running trains through the actual city centre are the Elizabeth line and Thameslink. If you count slightly outside the city centre, you could also consider the West London Line (southern and overground), and the other overground from Croydon to Islington to be throu-running. But they slightly miss the city centre.
desas
> Terminating a train and turning it around takes a lot of space, space that is usually unavailable in a city center.
This doesn't happen in London in my experience. Trains don't turn around, instead every train is double-ended. The driver gets out of the cab at the terminus, walks to the other end of the train and gets in the other cab. They can do it faster than the passengers disembark.
Animats
There are several solutions to turning around at a terminal. Sometimes there's a turnaround loop. Grand Central has two, one on each level. Older systems would detach the engine, rotate it on a turntable, and reattach it at the other end of the train. Double-ended trains are far more common today, since control from either end was solved long ago.
frosted-flakes
That's what turning around a train means. The point is that a train at a terminal station is "occupying" a disproportionately long section of track, and as a result you need a multi-tracking and a ridiculous number of platforms to allow storage of trains to handle enough trains... while a through-running station can achieve the same capacity with just two tracks and 2-4 platforms.
xg15
> while others, such as Cologne, have simply added platforms at their main stations to enable suburban trains to run through.
We did?
Cologne's tram system is weird. Over the last century, they merged the tram, subway and selected private railways into a single network. The result is sort of a tram network on steroids, that also runs underground and serves longer distances to two neighboring cities. But it's still separate from the national train network or even "real" suburban trains (S-Bahn).
(Edit: Just learned the term "interurban" for that...)
That's unlike Berlin or Vienna, where you sometimes have subway and S-Bahn side by side in the same station, but on different tracks. I think that's closer to what they mean with "through-running"?
croisillon
i can’t think of any side by side subway and s-bahn in vienna?
xg15
Was thinking of Quartier Belvedere, but seems to be subterranean S-Bahn only.
Maybe Wien Mitte though?
https://homepage.univie.ac.at/horst.prillinger/ubahn/m/large...
croisillon
no, Mitte is similar to Praterstern, you need a couple minutes between s and u platforms
xxmarkuski
> This caps capacity and reliability.
Karlsruhe: The local operators have severe quality issues, in part due to this concept. There are like four points in the city where issues impact the whole network. The rolling stock is very bad compared to the other regional trains running in Baden-Württemberg (no/bad ac, flaky internet, no sockets, bad seating). The trains have way too little capacity, I’ve seen incidents, where they run three coaches (which they don’t do often, they are too long to enter the city), where people could not get in anymore. Some of the stations in the surrounding area are absolutely mental (Durmersheim for example), you have to walk over rails where ICEs and cargo goes through. Some trains are split or merged when leaving or entering the city, but it always causes delays. When trains can’t use the heavy metal rails and thus not leave the city due to ICEs getting priority, a lot of inner city traffic can be affected. The cooperation between the different infrastructure operators is also a source of problems.
Do not take Karlsruhe uncritically as an example where this model works well, yeah sure average numbers make it look good, but the reliability is complete ass. KVV always manages to surprise me on how bad it gets.
trollied
Sheffield in the UK has tram trains - it was the first such implementation in the UK, and runs on national rail lines as part of the journey to Rotherham.
trgn
Brussels is a great example of a train briefly turning into a subway. There's pretty much never a fare check either, so it's essentially a free north south subway line at very high frequency.
standardUser
> A final model of light rail worth mentioning is interurbans. ...these systems were sometimes staggeringly expansive: at one point, it was possible to travel from Wisconsin to New York State exclusively by interurban.
I had no idea. A few systems are still in place: https://en.wikipedia.org/wiki/Interurban#United_States
fjfaase
See https://en.wikipedia.org/wiki/Tram-train for a more extensive list of tram train solutions world wide.
salynchnew
Weirdly sparse list, here.
Does San Francisco's Muni LRVs somehow not qualify as a tram train network?
https://www.sfmta.com/getting-around/muni/muni-metro-light-r...
puls
It doesn't because it doesn't use any mainline rail track. Imagine if the T-Third went onto the Caltrain tracks at Bayshore and continued down the peninsula instead of terminating at Sunnydale; that would be a tram-train.
It would also be more or less impossible under current US regulations, but there's always hoping that that could be fixed.
Animats
It would reduce both capacity and speed. That would put a slow, low-capacity tram on the same track as a fast train line with large trains.
Current Caltrain equipment: [1]
Scoundreller
> Tram-trains manage speeds about the same as the wholly tunneled Paris Metro.
Uhhh, it’s not.
E.g.
> Line 8 is 22.057 km (13.706 mi) long, including 2.8 km (1.7 mi) of open-air tracks in the southeastern suburbs.
https://en.m.wikipedia.org/wiki/Paris_M%C3%A9tro_Line_8
Maybe they just meant comparing it to the tunnelled sections but I also don’t see why that would really impact speeds. It’s the traffic/grade separation that gets you the speed advantage.
also the Paris Metro is kinda slow because of station density, so you may save a lot of walking but have a lot of station dwell time.
Go during the day and pick any two arbitrary points in Paris and you’ll usually find cycling faster than transit on Google Maps.
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Peteragain
In Melbourne we loved our Tram Trams that run down the middle of the street and hold up the traffic. The W class trams were all fazed out and replaced with "light rail". Bigger Faster Better. Not. Melbourne has a good mix of tram and train - yes you take athe train to the city (a through route via the underground loop) and get on a tram for the last km. Small frequent trams are better for this and require lighter track. I think there was a recent HN article to this effect.
Time to reinvent the Interurban https://en.wikipedia.org/wiki/Interurban