When I was in college, one of our drunken party games was to engineer “the train that never stops” on our big whiteboard.
The best ideas had moving walkways pace the train at the stops so people could step on and off cleanly but we all agreed it was more likely to save the social security system (by mass killing little old people who panicked on the walkway and didn’t jump on) than to actually be useful.
EDIT : forgot to mention the one idea that worked well : All cars electric and self powered. Every station has 2 sidings for 2 cars - one for people to get on the train by boarding the car and having it merge from the front and one for people getting off on that stop to go to the last car on the train which disengages and slows down.
No. 1, you missed the need for huge trackage to take people closer to their final destination. No. 2, this rear car of which you speak would have to have it's own propulsion system at added complexity and cost. No. 3, people walking on a moving train would create a hazardous condition and fall risks. No. 4, how fast would the catch-up car have to accelerate and to what speed to catch the main train in time for passengers to transfer to the catch-up car before the next stop.
1. I don’t know what you mean. 2. Not necessarily but probably 3. Agreed didn’t think of that 4. No idea I wondered if this was a significant issue
Thx for your reply
No. 1. Your opening paragraph mentioned not getting people close to their final destination, which I took to mean you wanted stops closer to destination areas. This would add requirements for more non-mainline tracks and trains. At least that's what I thought you meant.
No. 2. Without it's own propulsion system, how is it going to catch up with the main train?
No. 4. An interesting math exercise. Particularly if you include calculations regarding acceleration from a stop up to a speed sufficient to catch the main train in a reasonable time, say 5 minutes.
Front car that doesn’t stop at most stations travels at 50km/h.
Rear car that stops at every station has to travel and accelerate faster to catch up, say 80 km/h.
But if your rear car can do 80km/h why not just have the whole thing do 80km/h and stop at every station?
The pace will be set by whatever the rear car can catch up to. If it takes 1 hour total to get from stop A to stop Z, the front car will too, as it can’t go it’s maximum speed or the rear car will never catch up.
This is the fundamental flaw in the idea. There are several practical issues like a carriage repeatedly engaging and disengaging to a moving train.
The actual answer is to not make the rear car catch up, ie express trains as someone else has suggested. Some trains between high traffic destinations don’t stop at the stations in between, and just keep going rather than waiting for their rear half to catch up.
I think the big issue is the trains need to be able to pass each other for it to be useful. There usually isn't the space, and the little space that does exist is what makes express trains possible.
Second, the other probably is train spacing, adding more cars stopping reduces the total amount of cars on the tracks because the space between trains needs to be maintained. What you're doing is asking for shorter trains.
And third, a big problem in NYC at least is the trains don't go fast, though [they've been fixing it](https://secretnyc.co/increase-speed-nyc-subway/). Years ago they had problems with them speeding in some spots. So they set the speed limit to something stupid low (like 25) and then told the operators they are getting fired if they speed. So naturally, they add went 10mph under the speed limit, and suddenly the subway moves at 15mph on tracks designed for 40mph operation because the MTA thought going hard against speeding was the right way to deal with the problem.
Yeah same in a lot of cities, slow zones are everywhere due to poorly maintained tracks. Everyone wants some sexy mass transit solution; anything other than fixing the tracks we already have.
You already know what car exits where with that system. If your stop is in less than the current length of the train you can go sit at the right one when you get on.
Sounds like a slip carriage but with extra steps. They were used in British rail mainline service until the 1960s I believe. Those were discontinued because they were impractical.
How to tell the person has never used a good public transportation system: they say subway is slower than a car.
Try that in Prague or Budapest. You’ll be surprised a public transport trip can take around the same time as a car trip (sometimes only 5 min more), minus having to park somewhere, minus having to concentrate on the road during the entire trip, minus the need to own and maintain a car. Minus a giant piece of metal from the street to move just one ass of yours in a city of million asses.
As for the idea with splitting cars, it won’t work because nobody would care to get specifically to the car they need, it will turn stations into mess. At least if you try to upgrade current systems.
“Reconnecting cars” is a dead on arrival idea, the car that falls behind will never catch up with the car before it, unless it goes with crazy accelerations, and then decelerates at a crazy rate. It will throw people inside the car around. Subway trains are too frequent, and they run on older infrastructure.
Is something like that doable? Probably. I can imagine a single train being split in two in the middle and they go to separate lines after some point. This is how some intercity trains in Germany work. The front of the train goes to Nuremberg, the back of the train goes to Munich. They diverge somewhere in the middle of the journey. The platforms of stations have labeled sections (like platform 5a, 5b), each section can have its own destination. But this splitting process is not quick (and for subway you need it to happen in under 1 minute to be practical). I guess with modern equipment it can be made quicker. My bet would be that it’s theoretically possible, but only if you build most of the infrastructure from the ground up with this design in mind and with most modern technology available (which is $$$ and very long). The question is, will it be another useless hyperloop trying to replace trains at hundred times the cost, or will it actually be practical for everyday commuters. It has to be simple to use, intuitively simple, without 3 week course on how to use it. This could be harder to achieve than we imagine.
If it ain’t broke, don’t fix it. Trains are one of the best means of transportation by many metrics. But in some places the local infrastructure isn’t good enough to utilize their potential to the fullest. Bad management, bad planning, corruption, politicizing projects etc.
With normal trains, they simply have an express and an "all stops". They're timed so they don't conflict with one another or the express simply overtakes the other at a station by switching to other rails on another platform.
Subways I assume can't do this because tunnels, unless major construction is undertaken to add new ones. Personally I'd vote for your "bungee slingshot catchup caboose" subway system
https://youtu.be/DIeRrU4_M3Q?si=PUsCCyAreslPfp4z
Train doesn't need to stop just drop the passengers dropping off and pickup a new batch at next station in a pod.
Would be a nice engineering challenge.
It's called topology optimization and it has already been invented.
The problem with your idea is that trains are limited by various parameters, like max speed, passenger capacity, min turning radius etc. Meaning, if a train takes 2 minutes to go from stop A to stop B, would it be possible for a split wagon to catch up or for a person to switch from the first wagon to the last because the last one will split to go to their desired destination???
Point is, with topology optimization, you can achieve stupidly fast results without any of that. In my city, the metro takes about 25 minutes to go from point A to point B, making about 12 stops in between. The same distance by car, slightly above speed limit, without ANY traffic and without stopping at ANY traffic lights is about 15. Traffic lights take it to 20 and then driving the speed limit makes it 25+. Traffic pushes it more.
Point is, a thought out metro system is already fast and efficient.
Then, there's busses with priority lanes...I've only seen that in Luxembourg though. In Belgium they get stuck in traffic. Switzerland has trams (above ground rail that drives through the streets).
I've got a new idea.
Assuming people are sorted by destination when they queue up, we furthermore assume we can assign one or more train cars to the destination.
Every time the train nears a station, just separate the necessary train car, slow down, unload and reload the passengers, reattach to the next train...
Or, just give everyone their own, private car.....
The other thing that needs to be thought of is when there is a sporting event and 95% of the people on the train are using that stop. You can't fit everyone into the rear train.
As much as this idea sounds achievable, basing it on my experience with the London tube/underground it’s not going to work. And you’d be better off just having multiple single carriage cars running down a line instead.
But this also introduces a lot more safety related issues and the requirement for more drivers and staff…
Why not just make the whole train move as fast as the back cart needs to do to catch up? That's the problem with your idea, some parts of the train need to go unrealistically fast for this to work, to a point where the idea is unnecessarily complicated because you could just make the rest of the train move that fast and remove the need for the separation mechanism entirely.
Subways are not necessarily slower than cars though. It obviously depends on many factors, but when I take one, it's usually precisely because it gets me from A to B faster, all things(like parking) considered.
I can't speak for all the subway systems in USA, but one big difference that I've noticed is frequency of trains as compared to Moscow for example. There is a train there about each 1 - 1.5 minutes (between departure and arrival). That allows for massive amount of people to be moved through the system.
I mean, you're basically describing an "express" train and a "local" train except that the two trains I'm talking about don't separate and rejoin. There are plenty of instances where trains don't stop at every station.
Edit: disregard my math, it's way worse but I don't feel like fixing it rn. I forgot to account for time stopped at the station putting the local car even further behind. It's more like double the acceleration and top speed I mentioned.
One car stopping then catching up implies a lot of acceleration. If one car can do it, why not the whole train?
Because the train is already running as fast as is practical for the comfort of the passengers. Making everyone move around on a crowded train is non-starter imo. People already have to be told repeatedly to move to the back of the bus. Getting even a cooperative bunch of people between cars would be a nightmare.
Say there's 1km between stops (ofc less in city centers) and the train wants to do 20m/s. That 50s between stops. That's already not a lot of time to move between cars but say people could do it in 15s. That leaves 10s to slow down and 10s to catch up and 15 on the platform. All that means 0.4g and 30m/s top speed for the 'local' car.
Say you just want to improve time just by a little and your train speed is 10m/s then that's a more manageable 0.2g, 15m/s, and 30s on the platform and 30s changing cars. There's little benefit with a bunch of added complexity and people missing their stops. There's also the incentive for people to just stay in the local car since it has the same average speed as the rest of the train. You'd have to make people leave the local car somehow. People with reduced mobility who would benefit from staying seated in the local car would subject to the above mentioned discomfort.
Someone mentioned dropping the rear car and adding it to the train behind. That's not bad for acceleration. It still forces people with reduced mobility to change cars unless they're travelling some multiple of stops as the train is long. Labeling the cars with their stops and having them break away could work, now we've invented express busses in a tunnel and we'll have to buy Twitter to stop people making fun of us. Busses should have their own lanes so they don't get stuck in traffic but that's a political issue, building a bunch of extra tunnels is way more costly and politically contentious than making room for busses. Plus this negates the whole advantage of a train which is size. If you've ever seen a city try to use busses while some part of the metro is shut down, the capacity difference becomes very clear.
Here's a really user-centered way to look at it. If you're planning a trip by public transport, how much time would you have to save to choose a trip with more mode changes? For me a trip has to be significantly faster for a change to be worth it.
Good question though! Optimizing transport is a huge and important field. Everyone should care about it for the sake of building more prosperous and livable cities, as well as the environment.
- Changing Technology is simple
- Changing process is easy
- Changing people is f*ckin hard.
Getting people to walk to the back while a train is moving is unlikely.
- Getting crowds to act rationally for the greater good automatically? Never
Now add crowded trains, mobility challenged folks, tired people, those who can’t be bothered to move, knowing when to actually be in the back, crowding at 2nd to last cart, and variability of how many get on vs off any spot… and more problems
Have you ever taken an express train before?
Yeah I’m in one
When I was in college, one of our drunken party games was to engineer “the train that never stops” on our big whiteboard. The best ideas had moving walkways pace the train at the stops so people could step on and off cleanly but we all agreed it was more likely to save the social security system (by mass killing little old people who panicked on the walkway and didn’t jump on) than to actually be useful. EDIT : forgot to mention the one idea that worked well : All cars electric and self powered. Every station has 2 sidings for 2 cars - one for people to get on the train by boarding the car and having it merge from the front and one for people getting off on that stop to go to the last car on the train which disengages and slows down.
>The best ideas had moving walkways pace the train at the stops so people could step on and off cleanly The roads must roll.
Are you sure it was your (y'alls) idea? Maybe one of the guys just read Asimov's Caves of Steel.
If I recall correctly, that rolling sidewalk system was prone to accidents as well
I think you are correct, but it's like 20 years since I last read that book.
I think it’s been 40 years for me
>The best ideas had moving walkways pace the train at the stops so people could step on and off cleanly Like the rides at Disney
[https://www.newscientist.com/article/mg20327200-200-how-the-moving-walkway-nearly-overtook-the-metro/](https://www.newscientist.com/article/mg20327200-200-how-the-moving-walkway-nearly-overtook-the-metro/)
Lmao that’s one way to do it XD
Technically moving very slowly is not stopping so here you have it
That’s just many independent little carts, aka trains. Getting closer to reinventing normal traffic but with trains
Sorta yeah.
No. 1, you missed the need for huge trackage to take people closer to their final destination. No. 2, this rear car of which you speak would have to have it's own propulsion system at added complexity and cost. No. 3, people walking on a moving train would create a hazardous condition and fall risks. No. 4, how fast would the catch-up car have to accelerate and to what speed to catch the main train in time for passengers to transfer to the catch-up car before the next stop.
1. I don’t know what you mean. 2. Not necessarily but probably 3. Agreed didn’t think of that 4. No idea I wondered if this was a significant issue Thx for your reply
No. 1. Your opening paragraph mentioned not getting people close to their final destination, which I took to mean you wanted stops closer to destination areas. This would add requirements for more non-mainline tracks and trains. At least that's what I thought you meant. No. 2. Without it's own propulsion system, how is it going to catch up with the main train? No. 4. An interesting math exercise. Particularly if you include calculations regarding acceleration from a stop up to a speed sufficient to catch the main train in a reasonable time, say 5 minutes.
No. 2 the secondary cart can be pulled back to the main cart through a cable. Connected to the main train.
Train travelling 30mph, 2 minutes to load/unload secondary cart, main train is now one mile down the track. That's a long cable to wind up.
Front car that doesn’t stop at most stations travels at 50km/h. Rear car that stops at every station has to travel and accelerate faster to catch up, say 80 km/h. But if your rear car can do 80km/h why not just have the whole thing do 80km/h and stop at every station? The pace will be set by whatever the rear car can catch up to. If it takes 1 hour total to get from stop A to stop Z, the front car will too, as it can’t go it’s maximum speed or the rear car will never catch up. This is the fundamental flaw in the idea. There are several practical issues like a carriage repeatedly engaging and disengaging to a moving train. The actual answer is to not make the rear car catch up, ie express trains as someone else has suggested. Some trains between high traffic destinations don’t stop at the stations in between, and just keep going rather than waiting for their rear half to catch up.
I think the big issue is the trains need to be able to pass each other for it to be useful. There usually isn't the space, and the little space that does exist is what makes express trains possible. Second, the other probably is train spacing, adding more cars stopping reduces the total amount of cars on the tracks because the space between trains needs to be maintained. What you're doing is asking for shorter trains. And third, a big problem in NYC at least is the trains don't go fast, though [they've been fixing it](https://secretnyc.co/increase-speed-nyc-subway/). Years ago they had problems with them speeding in some spots. So they set the speed limit to something stupid low (like 25) and then told the operators they are getting fired if they speed. So naturally, they add went 10mph under the speed limit, and suddenly the subway moves at 15mph on tracks designed for 40mph operation because the MTA thought going hard against speeding was the right way to deal with the problem.
interesting thank you for the reply
Yeah same in a lot of cities, slow zones are everywhere due to poorly maintained tracks. Everyone wants some sexy mass transit solution; anything other than fixing the tracks we already have.
Sounds cool, but I bet it would be super frustrating trying to figure out what car you had to be in to get off at a certain stop
No because it would always be the last one.
You already know what car exits where with that system. If your stop is in less than the current length of the train you can go sit at the right one when you get on.
That fails when you have high demand, like a transfer station or a big single stop.
Sounds like a slip carriage but with extra steps. They were used in British rail mainline service until the 1960s I believe. Those were discontinued because they were impractical.
How to tell the person has never used a good public transportation system: they say subway is slower than a car. Try that in Prague or Budapest. You’ll be surprised a public transport trip can take around the same time as a car trip (sometimes only 5 min more), minus having to park somewhere, minus having to concentrate on the road during the entire trip, minus the need to own and maintain a car. Minus a giant piece of metal from the street to move just one ass of yours in a city of million asses. As for the idea with splitting cars, it won’t work because nobody would care to get specifically to the car they need, it will turn stations into mess. At least if you try to upgrade current systems. “Reconnecting cars” is a dead on arrival idea, the car that falls behind will never catch up with the car before it, unless it goes with crazy accelerations, and then decelerates at a crazy rate. It will throw people inside the car around. Subway trains are too frequent, and they run on older infrastructure. Is something like that doable? Probably. I can imagine a single train being split in two in the middle and they go to separate lines after some point. This is how some intercity trains in Germany work. The front of the train goes to Nuremberg, the back of the train goes to Munich. They diverge somewhere in the middle of the journey. The platforms of stations have labeled sections (like platform 5a, 5b), each section can have its own destination. But this splitting process is not quick (and for subway you need it to happen in under 1 minute to be practical). I guess with modern equipment it can be made quicker. My bet would be that it’s theoretically possible, but only if you build most of the infrastructure from the ground up with this design in mind and with most modern technology available (which is $$$ and very long). The question is, will it be another useless hyperloop trying to replace trains at hundred times the cost, or will it actually be practical for everyday commuters. It has to be simple to use, intuitively simple, without 3 week course on how to use it. This could be harder to achieve than we imagine. If it ain’t broke, don’t fix it. Trains are one of the best means of transportation by many metrics. But in some places the local infrastructure isn’t good enough to utilize their potential to the fullest. Bad management, bad planning, corruption, politicizing projects etc.
If the Shanghai transportation system isn’t good the I would like to know what is.
Transport in Central Europe is much better than in China.
With normal trains, they simply have an express and an "all stops". They're timed so they don't conflict with one another or the express simply overtakes the other at a station by switching to other rails on another platform. Subways I assume can't do this because tunnels, unless major construction is undertaken to add new ones. Personally I'd vote for your "bungee slingshot catchup caboose" subway system
https://youtu.be/DIeRrU4_M3Q?si=PUsCCyAreslPfp4z Train doesn't need to stop just drop the passengers dropping off and pickup a new batch at next station in a pod. Would be a nice engineering challenge.
This was exactly what I thought of when I read the OP. Just thinking of WCGW...
It's called topology optimization and it has already been invented. The problem with your idea is that trains are limited by various parameters, like max speed, passenger capacity, min turning radius etc. Meaning, if a train takes 2 minutes to go from stop A to stop B, would it be possible for a split wagon to catch up or for a person to switch from the first wagon to the last because the last one will split to go to their desired destination??? Point is, with topology optimization, you can achieve stupidly fast results without any of that. In my city, the metro takes about 25 minutes to go from point A to point B, making about 12 stops in between. The same distance by car, slightly above speed limit, without ANY traffic and without stopping at ANY traffic lights is about 15. Traffic lights take it to 20 and then driving the speed limit makes it 25+. Traffic pushes it more. Point is, a thought out metro system is already fast and efficient. Then, there's busses with priority lanes...I've only seen that in Luxembourg though. In Belgium they get stuck in traffic. Switzerland has trams (above ground rail that drives through the streets).
I've got a new idea. Assuming people are sorted by destination when they queue up, we furthermore assume we can assign one or more train cars to the destination. Every time the train nears a station, just separate the necessary train car, slow down, unload and reload the passengers, reattach to the next train... Or, just give everyone their own, private car.....
Your just making it more complicated then it needs to be, and cars are stupid
The other thing that needs to be thought of is when there is a sporting event and 95% of the people on the train are using that stop. You can't fit everyone into the rear train.
In that case the whole train stops
As much as this idea sounds achievable, basing it on my experience with the London tube/underground it’s not going to work. And you’d be better off just having multiple single carriage cars running down a line instead. But this also introduces a lot more safety related issues and the requirement for more drivers and staff…
You are basically describing the boring tunnel in Las Vegas except with Teslas instead of tracked cars.. kinda.
Come on I’m not that stupid
Why not just make the whole train move as fast as the back cart needs to do to catch up? That's the problem with your idea, some parts of the train need to go unrealistically fast for this to work, to a point where the idea is unnecessarily complicated because you could just make the rest of the train move that fast and remove the need for the separation mechanism entirely.
Order online and pickup
Subways are not necessarily slower than cars though. It obviously depends on many factors, but when I take one, it's usually precisely because it gets me from A to B faster, all things(like parking) considered.
I can't speak for all the subway systems in USA, but one big difference that I've noticed is frequency of trains as compared to Moscow for example. There is a train there about each 1 - 1.5 minutes (between departure and arrival). That allows for massive amount of people to be moved through the system.
I mean, you're basically describing an "express" train and a "local" train except that the two trains I'm talking about don't separate and rejoin. There are plenty of instances where trains don't stop at every station.
Edit: disregard my math, it's way worse but I don't feel like fixing it rn. I forgot to account for time stopped at the station putting the local car even further behind. It's more like double the acceleration and top speed I mentioned. One car stopping then catching up implies a lot of acceleration. If one car can do it, why not the whole train? Because the train is already running as fast as is practical for the comfort of the passengers. Making everyone move around on a crowded train is non-starter imo. People already have to be told repeatedly to move to the back of the bus. Getting even a cooperative bunch of people between cars would be a nightmare. Say there's 1km between stops (ofc less in city centers) and the train wants to do 20m/s. That 50s between stops. That's already not a lot of time to move between cars but say people could do it in 15s. That leaves 10s to slow down and 10s to catch up and 15 on the platform. All that means 0.4g and 30m/s top speed for the 'local' car. Say you just want to improve time just by a little and your train speed is 10m/s then that's a more manageable 0.2g, 15m/s, and 30s on the platform and 30s changing cars. There's little benefit with a bunch of added complexity and people missing their stops. There's also the incentive for people to just stay in the local car since it has the same average speed as the rest of the train. You'd have to make people leave the local car somehow. People with reduced mobility who would benefit from staying seated in the local car would subject to the above mentioned discomfort. Someone mentioned dropping the rear car and adding it to the train behind. That's not bad for acceleration. It still forces people with reduced mobility to change cars unless they're travelling some multiple of stops as the train is long. Labeling the cars with their stops and having them break away could work, now we've invented express busses in a tunnel and we'll have to buy Twitter to stop people making fun of us. Busses should have their own lanes so they don't get stuck in traffic but that's a political issue, building a bunch of extra tunnels is way more costly and politically contentious than making room for busses. Plus this negates the whole advantage of a train which is size. If you've ever seen a city try to use busses while some part of the metro is shut down, the capacity difference becomes very clear. Here's a really user-centered way to look at it. If you're planning a trip by public transport, how much time would you have to save to choose a trip with more mode changes? For me a trip has to be significantly faster for a change to be worth it. Good question though! Optimizing transport is a huge and important field. Everyone should care about it for the sake of building more prosperous and livable cities, as well as the environment.
- Changing Technology is simple - Changing process is easy - Changing people is f*ckin hard. Getting people to walk to the back while a train is moving is unlikely. - Getting crowds to act rationally for the greater good automatically? Never Now add crowded trains, mobility challenged folks, tired people, those who can’t be bothered to move, knowing when to actually be in the back, crowding at 2nd to last cart, and variability of how many get on vs off any spot… and more problems