Tram Trains

> 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.

> 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.

Amsterdam used to have a line to Amstelveen that ran trams and metros on the same track. The main disadvantage is the different platform heights, so you got very long platforms, half at tram height and half at metro height.

I think they stopped it. As far as I know, Amsterdam's tram, metro and train lines are entirely separate again. They may still have some connections, but if so, those aren't used for regular service.

As for the through problem, the main problem here was that many cities were already big before trains were introduced, and most didn't want to demolish large chunks of the city to make space for trains to the center (although American cities infamously later demolished their city centers to make space for cars). Amsterdam was on a big waterfront, however; the original 15th century port that wasn't being used anymore. The port moved east, and a new island would host the new central station right in the heart of the city. Although the city did lose its view of the waterfront.

Edinburgh drained a lake to make space for the train station. And of course some cities did demolish houses to make space for trains.

Time to reinvent the Interurban https://en.wikipedia.org/wiki/Interurban

> 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"?

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_...

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.

Alon Levy has also written some more on Tram-Trains: https://pedestrianobservations.com/2020/11/03/tram-trains/

A few points I want to add: The Stadtbahn (called Tram-Metro in this Article) is usually just as fast in the outlying areas as in the inner areas and rarely street running, just doing it with less infrastructure. It's just that rail tracks are even faster.

There are quite a few newly built S-Bahn Tunnels in cities under a Million in Germany, in Frankfurt, Stuttgart and Leipzig (you could quibble about citie vs metro area population).

The major downside of Tram-Trains compared to S-Bahns, Rapid Transit or just through running away from the city center is that they slow way down in the city center, much more than the other options. This makes it a bad fit for the sprawly, north american cities without a strong center which have much more demand for non city center destinations and a much more expansive center compared to european cities with tram-trains.

The big benefit of Tram-Trains is the flexibility. Over a region, some sections can implement their own new through running section for the Network (Heilbronn), be almost a metro (the Kombilösung and some parts of S11) or provide S-Bahn style service (e.g. Freudenstadt for a mediocre Regio S-Bahn).

But it's a master of none: Too slow and cramped for high-quality regional services, too few doors for rapid passenger exchange, too demanding and expensive (electrification and vehicles) for connecting small rural lines, legally limited in capacity (75m) for very busy services.

They can be great, but it really depends on local circumstances.

Before converting commuter rail to Tram-Trains, most American cities should first implement a frequent (at least 2tph), all-day, regular service with more urban stations for commuter rail and perform true ticket integration between mainline rail and their other urban transport (the ticket integration is very important!). This also applies to many european cities, such as in France, Spain, Belgium, ... .

See https://en.wikipedia.org/wiki/Tram-train for a more extensive list of tram train solutions world wide.

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.

This is a more nuanced summary than you often see; honestly tram trains have always seemed like an extremely overhyped solution, only one step down from out-and-out gadgetbahns. Yes there are a handful of cities in which they apparently work ok. But they're far from the magic bullet certain kinds of transport fan want to portray them as. Often what your city needs is just a regular tram, or a regular train, or maybe even just integrated ticketing so that people can easily change from the train to the bus.

> 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

We have such a train in Zürich as well. It's called the Forchbahn [1]. It switches from 600v to 1200v half way through it's trip. There is also the Uetliberg Bahn (but that can't be considered a Tram) which has an offset pantograph[3] in order to travel all the way into the city as one is AC and the other is DC. [2]

[1] https://en.wikipedia.org/wiki/Forch_railway

[2] https://en.wikipedia.org/wiki/Sihltal_Z%C3%BCrich_Uetliberg_...

[3] https://youtu.be/T10puRXXBA8?si=trhIXOhv0ziSNwL-&t=522

Metz in France has a tram like bus which travels through the city, partially on roads closed for normal traffic. The deal was, that the operator had to plan the routes to reach various. important points, like hospitals, schools, universities and large employers.

If you visit Metz, its easy to book a motel at the outskirts near an end stop of the train. Parking your car is free if you ride the train, the ticket serves as the exit ticket for the parking area too.

https://fr.wikipedia.org/wiki/Mettis_(bus_%C3%A0_haut_niveau...

> 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.

One thing missing from the article is that Manchester also had some disused railway line routes which could have new track laid on them relatively easily.

I think an easy win for tram/tramtrain systems would be to have capacity to move cargo, either in rollcages like grocery shops use, or on pallets with dollies from a peripheral location, to city center locations and eliminate at least some light goods vehicles. The problem is, it would probably be a very inefficient use of labour to have humans do all the last few hundred yards pushing.

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.

Some combination of interurbans and golf cart cars and electric scooters and electric skateboards would make a marvelous urban transportation milieu.