Quick Note: RER and S-Bahn Line Length
An email correspondent asks me about whether cities should build subway or commuter rail lines, and Adirondacker in comments frequently compares the express lines in New York to the RER. So to showcase the difference, here are some lines with their lengths. The length is measured one-tailed, from a chosen central point.
| Line | Central point | Length (km) |
| RER A to MLV | Les Halles | 37 |
| RER A to Cergy | Les Halles | 40.5 |
| RER B to CDG | Les Halles | 31 |
| RER B to Saint-Rémy | Les Halles | 32.5 |
| RER D to Malesherbes | Les Halles | 79 |
| Crossrail to Shenfield | Farringdon | 34 |
| Crossrail to Reading | Farringdon | 62.5 |
| Thameslink to Brighton | Farringdon | 81 |
| Thameslink to Bedford | Farringdon | 82 |
Express subway lines in New York never go that far; the A train, the longest in the system, is 50 km two-tailed, and not much more than 30 km one-tailed to Far Rockaway. The Berlin S-Bahn is about comparable, in a metro area one quarter the size.
Pedestrian Observations 
I don’t think there’s really a firm distinction between subway and commuter rail. Modern commuter rail uses electrification and high platforms like a subway, some segments of commuter lines, like the Montclair-Boonton line from Watessing to Montclair State University, have stop spacing as tight as modern subways while many American subways like the Washington Metro have wide stop spacing and long lines like commuter rail.
IMO the reason why many lines fall into two “clumps” of metro and commuter rail is that if most of the demand on a rail line is close in, generally it should have tight stop spacing and high frequency service, whereas lines where demand is mostly far out of the city generally warrant wide stop spacing and service at lower frequencies with larger trains. Perhaps instead of thinking “should this be a subway or a commuter rail line” cities should consider the different features– stop spacing, grade crossings, service frequency, ability to through-run with other lines– individually and then choose the mode based on those instead of starting with a mode choice.
Yeah, so the issue is that in most cases, you’re never getting a line 40 km out of city center entirely greenfield. There are exceptions in some extremely strong circumstances, including both of the RER A branches in the table, but that’s not most of the RER, and the amount of TOD at Marne-la-Vallée and Cergy is atypical. Even the A to Far Rockaway had to take over an LIRR branch.
Is it “can’t” or “don’t have to”? Most cities built plenty of greenfield lines far out, just a very long time ago so that we no longer consider them greenfield. They simply have no need to build greenfield lines far out today, and can focus on city centre capacity.
Chinese cities have few legacy lines, so they do have lots of very long greenfield lines under construction.
If you allow combining the length of Paris line 17 and line 14 together, that’s a 34km line from Châtelet under construction right now. Maybe Paris also has a lack of legacy lines in the suburbs.
Of course if an existing rail right of way has electrification and high platforms, it wouldn’t make sense to convert it to a metro which would use a different loading gauge and electrification standard, but in the US, there are a lot of lines that have neither. If freight and intercity trains can be kicked off such a rail line, I don’t see why turning it into a subway extension would be much more expensive than modernizing it as commuter rail.
I don’t feel like having a fully greenfield right of way is a requirement to be a subway either, considering how many US subways use mainline rail rights of way.
I’m not impressed by length, I’m impressed by function. It’s not how long it is, it’s what you do with it. I see expressness not the infrequent trains occasionally wandering out to the far tendrils with a few people.
There is enough demand along Queens Blvd for there to subway trains that make all the stops, subway trains that make few stops, LIRR trains that make all the stops and LIRR trains that don’t. …. The train from Ronkonkoma can surf through most of Queens, express, while other trains make the local stops whether that’s an M or an R on the subway or an LIRR train.
The A train took over an LIRR branch because politicians were too spineless to tell the few people out in the Rockaways to take a bus to the mainland. That might be because they were still stunned and bedazzled by whatever gave the LIRR the urge to build a third way to get to Far Rockaway.
https://en.wikipedia.org/wiki/Cedarhurst_Cut-off
I’m not impressed by length, I’m impressed by function. It’s not how long it is, it’s what you do with it.
[snicker]
What are the frequencies at those lengths?
For example, Barcelona – Mataró – Maçanet line is in theory 73 km long, but only one train per hour reaches this extreme. Mataró, the main stop in the line, has 6 trains per hour (and even more in peak hour), but it’s only one third of the way. So they are both branded together as Rodalies, but they are actually very different services.
is length, frequency, or something else, the most useful way to classify services?
For the Elizabeth Line Shenfield has full service so that is fair. Otherwise the other branch to the East is Abbey Wood which is 19km from the centre.
To the West Heathrow is 29km and Maidenhead is 42km from the centre, both of which are probably the fairer comparisons than Reading which has a fairly limited service.
(Of note I am using Tottenham Court Road as the centre for these)
For Thameslink perhaps St Albans which is roughly 30km out might be fairer?
But link yeah I think the overall point stands, the A train is by far the longest out and it is the only one that is vaguely comparable to the Thameslink/Elizabeth lines
Also the A train is slow. It takes 1h40 from Far Rockaway to Inwood vs 1h03 from Abbey Wood to Heathrow Terminal 4.
The A-train takes 75 minutes from JFK to Columbia Presbyterian Medical Centre (way up in Harlem), about 32km. That’s excluding the shuttle from airport to the station. (I’ve not done it since the AirTrain.)
RER-B3 from Paris-CDG to Gare du Nord is 32km and express service is 30m and stopping service is 35m.
RER-D from Paris-Chatelet to Evry (new town for hi-tech 38km south-east) takes 45 minutes.
Yes, the A-train is painfully slow, and bloody longitudinal seating the whole way …
If it was so execrable why didn’t you use one of the alternatives? There were and are many alternatives.
There are? I’d bet using the AirTrain would end up being as long. And you know coming from the airport a one-seat ride has certain attractions. You need to tell us about some magical route and the travel times including transfers. (Helicopters & Ubers not allowed.)
My point about the RER is that it covers similar longish distances far quicker, and in better comfort. That was one of its main points when replacing the Transiliens, not just the thru-function in Paris. Linking those 1960s new towns like Evry at 30 to 45 minutes not an
excruciatingexecrable 75 minutes. You might get BoBos like me and Alon to hop on a RER for a 30 minute zip to the banlieus but a 75 minute crawl on a Transilien from the 19th century?RER-B from CDG is 2.5 times faster than the A-train.
The RER doesn’t go to JFK. It doesn’t go outside of metro Paris much. I do hope this isn’t a revelation, it isn’t an option for places it doesn’t go.
It’s not my problem you didn’t check the Port Authority’s website for transportation options. Uber wasn’t one of them when you took your purported trip. Purported because the A train has perpendicular seating. They may be occupied but it has perpendicular seating And longitudinal seating. No one forced you to take the A train or sit in a seat.
There were and are Greyhound style buses between all of the airports and Manhattan. There are shared ride vans that will drop you at your destination like a cab will. There are rental cars. Or having someone pick you up. Or being an especially frugal masochist and taking a city bus to the subway.
There is never going to be a one seat ride from the airports because Airtrain is good enough. And will be there for trips outside the imagination of clueless railfans. Like to the parking lots. Or the rental cars. Or the drop off/pick up lot. Or the hotel shuttles. Or the parking lot shuttles for masochists who didn’t use the expensive lots.
@adirondacker12800, Heathrow and CDG are both a similar distance outside the city to JFK…
That’s nice. Just like the RER doesn’t go to JFK the Elizabeth line doesn’t go to CDG. What’s your point? No one is stopping you from using CDG or LHR.
……..I do hope this isn’t a surprise. Flying to London isn’t an effective way to get to New York. Neither is flying to Paris.
It has half service. Roughly half the trains go between the core and Abbey Wood and half go to Shenfield. Except for the trains, that I’m sure will give certain railfans the vapors and have them take to their fainting couch, the trains that originate at Gidea and terminate at Liverpool Street.
Malesherbes, Reading, and the Thameslink tails are extreme outliers. Thameslink in particular is an unusual case where longer-distance trains were routed into the tunnel while much shorter-distance trains to e.g. Caterham and Tattenham Corner using the same approach to London still stub-end at London Bridge. Malsherbes is served by an hourly shuttle from Juvisy offpeak, and Reading only two Elizabeth Line trains per hour, on systems where the primary segments are an order of magnitude more frequent.
Distances for *all* the Paris RER tails, measured to their outermost point with every-20-minute offpeak service thru from the core (even if a small number of trains go futher):
The NYC A train is 32.6km from 42nd St to Far Rockaway, making it exactly median for an RER tail. The A is of course itself an outlier among subway lines, but even the NYC N train at 23.6km from Times Square to Coney Island is longer than some Paris RER tails.
That said, while Adirondacker is right that there is significant overlap between NYC subway line length and other cities’ RER/S-Bahn line length, I’m unclear how he considers this to be any sort of argument against your regional rail proposals. Certainly “there are already some shorter-distance RER-like services running thru” is no reason not to additionally run longer-distance services thru. Nor does a service being very long mean it can’t serve short trips nearer the core; local Watford Junction-London Euston fares are valid on London Northwestern services that began in Birmingham, and local Amsterdam Amstel-Amsterdam Centraal fares are valid on NS InterCity services that began in Maastricht, so why shouldn’t local NYC fares be valid from Jamaica to NY Penn on services that began in Ronkonkoma?
I think Adirondacker thinks Alon’s regional rail proposals — the infills, the GCT to Fulton segment (let alone the Upper Bay Tunnel), the lines beyond the original three lines and Erie-Atlantic — bleed into overkill, and expanding crosstown coverage and filling in more rapid transit deserts has much better marginal per rider capex and opex than the SI Tunnel, infill stations, and Lines 6 and beyond.
Okay, that’s at least my current take. …
I think most of our peers have done more aggressive tunnelling than a fixed link from the mainland to the Isle of Wight, and certainly a Staten Island tunnel is less ambitious than that.
Certainly the Faeroes island tunnels or a lot of the Austrian tunnelling is more out there than a tunnel to the Isle of Wight.
There are many other tunnels to consider. Speculative because they’ve need more capacity under the Hudson to Penn Station for 30 years and they are still dawdling. We’ll both be dead before either project gets seriously considered. Either could likely be sunken tube instead of bored tunnel. Sunken tunnel was possible in the past because it was just river mud. Today it’s toxic waste.
Jersey City to Brooklyn would be shorter and serve a lot more people. There could be all sorts of through running and timed cross platform transfers. And it keeps people out of Midtown because people who want to go Downtown don’t need to go through Midtown to get there. Alon wants to send all of them to Bergen County. Apparently because moving trains is the goal instead of moving people. The demand is in Newark which is in Essex County.
I think a tunnel could go to Brooklyn and the train runs express to Manhattan.
One cannot say in the abstract how many lines are needed. It depends on how full the lines are now and how much potential ridership will change in the future. If the NYC area is upzoned to meet market demand, there could be millions of potential new riders, and Alon’s full system would be needed. Even if not, it is better to build small rail projects in a way that’s compatible with possible large projects in the future, and looking at Alon’s large plan (or a similar proposal) makes this possible.
It does seem that the main purpose of extending Metro North south would be to relieve the subway, particularly the Lexington. But since covid and the first segment of SAS, the subway is not so busy. It could be further relieved by building a regional rail tunnel from Brooklyn to New Jersey, making transfers from NJT/LIRR to the subway to reach Lower Manhattan unnecessary. At that point, one could do without a Metro North southward extension for a long time, but of course the Brooklyn-NJ tunnel should have provisions for an interchange with it.
From St. George in Staten Island to 65th St. on the border between Bay Ridge and Sunset Park in Brooklyn? Where the Port Authority and Conrail want to send freight trains? Something railfans forget about when they they are working up a frothy batch of foam over the Triboro or whatever the Governor is calling it this week? Add a million people to Long Island they are going to want all the stuff current people want. An increase of 12.5 percent. Which means 12.5 percent more freight going in and 12.5 percent more garbage and recyclables going out. The roads teeter on the brink of gridlock quite often and adding 12.5 more trucks would not be helpful…. Having subway isn’t very useful if you can’t get food, because it is stuck in gridlock in New Jersey.
It would be a slightly longer route but likely cheaper because lots of it would be on land instead of under the harbor. Two stops in Brooklyn that they might find useful. A station at the 8th Ave stop on the Sea Beach Line, today’s N and W, means they could connect to the N and W there and to Triboro. Railfans will plotz. Continuing onto where the LIRR terminal on Flatbush Ave is now, would mean they and Metro North passengers would have a one seat ride to Barclay’s Center and most of the subway lines in Brooklyn.
@adirondacker12800, the north London line has 8tph all day and freight.
20 million people on Long Island and in New England will generate a lot of freight. Partly because assembling North American freight trains is far less labor intensive than European ones. Having a subway isn’t much good if your food is stuck in gridlock. Unpleasant if your garbage can’t be shipped out either. Though that will stop – generating garbage – once the food runs out.
One can say, in the abstract, that short of some dystopian depopulation of the Midwest, or something similar, the population of metro New York will grow slowly. And likely begin to decline along with the rest of the world sometime later this century. Lots of places have been upzoned. The people living there don’t want to die so someone can buy the property and redevelop it. Rude of them to spoil railfan fantasies, isn’t it?
Arithmetic rears it ugly head. If 5 million people manage to stuff themselves into Metro New York that will be a 25 percent increase. And because that will make the terrible traffic, gridlock, increase demand for trains. Double would be reasonable, not five or six times as much. Stuffing 5 million people in would be extraordinary.
Someone lent Alon the box with 64 crayons and an attempt was made to use all of them.
Why does this topic elicit such a strong reaction from you?
I like crayons. I like Alon. Alon is trying to make a living at this. Splattering hilarious fantasy maps doesn’t help with that.
The case against integration of the subways and buses with the commuter rail is the one Jarrett Walker put out: Integration works in smaller geographic areas with homogenous transportation needs. … Because when you integrate one thing, you disintegrate the other. … In particular, you give people in far off lands who don’t really use much transit service veto power over more frequent service. https://humantransit.org/2015/08/on-transit-integration-or-seamlessness.html.
Jarrett’s argument is arguably applicable to administrative/governance integration but that need not have anything to do with fare integration. Every German metro area has a Verkehrsverbund handling fare integration between at least half a dozen administratively independent operating agencies. London travelcards and Oyster local fares are accepted on most regional rail services making multiple stops within the London zones even though the train operating companies are governed entirely independently of Transport for London; people in Birmingham or Milton Keynes where some such trains begin their journeys certainly don’t have veto power over more frequent service within London. Conversely, the New York Subway has been governed by the same agency as LIRR and Metro North for decades without any fare integration.
I’ll bite. Again. I’m in Elmhurst at Broadway and Elmhurst Ave. I can see where the LIRR platforms used to be. The ones the MTA closed for lack of interest. I want to get to work in Rockefeller Center. The LIRR station has magically reopened. Do it take the LIRR to Penn Station and a long walk to Herald Square for an M train to Rockefeller Center or take the M train from Broadway and Elmhurst Ave. directly to Rockefeller Center? Though the R train is a half-ish block away that might work better depending on which specific building in Rockefeller Center I’m headed to.
It works that way for many other trips because clueless railfans from the hinterlands think the only origin is Jamaica and the only destination is Madison Square Garden or the Empire State building.
….. If I wanted to get to the World Trade Center I could take an M or an R one stop and walk across the platform to an E train instead of changing in Penn Station.
… Onux thinks I’d be stupid enough to take a train from New Jersey to 125th Street and Park Ave. , through a duplicate of East Side Access to take a very long walk or a bus ride crosstown, to get to the Apollo Theater. When I can get off the train in Penn Station and use the A train to get much closer to it. Just as express as the Metro North tracks.
I’ll bite. Again. Which lines are you going match up with what? Sending NJTransit trains to Grand Central and through to Metro North territory means they can’t go to Long Island. If you send them through to Long Island they can’t go to Metro North. There are more than one line hiding in a single color on the maps. Trenton Local versus Jersey Ave. Local. or a Trenton Local. Or a Stamford Local versus a New Haven Express. It’s not railfan blue and red line crossing each other. It’s well over a dozen lines and it’s shaped like a “Y” not cruciform.
Clueless railfanery is Yale undergrad going to Princeton to boink. Works out real well if the New Haven Express gets paired up with the Trenton Express. It doesn’t work out too well if it’s Yalie and someone from Fairleigh Dickinson because the trains to either campus are paired up with trains to Long Island. Or the Trenton express goes to some magical mystical through running place on Long Island. The New Haven Express could become the express to Dover via the Boonton line and that fouls up Princeton or Fairleigh.
Before converting Grand Central to a twin of East Side Access and four tunnels to Penn Station, the clueless railfans wet dream, I’d spend the money on a duplicate of East Side Access vaguely parallel to Fulton Street in the financial district. To connect NJtransit to the LIRR. Which actually solves problems instead of scratching clueless railfan’s itches.
Define your goals. Getting people from New Jersey to the East Side doesn’t require stopping in Penn Station New York. Going to work on Wall Street doesn’t have to involve Midtown.
Can anyone understand this?
I’m sure the railfans who think I just don’t understand will be able to tell me why I don’t understand.
Can you please try to clarify what you are trying to argue for or against? Claims it sounds like you might be making (with my responses in parentheses):
1. It’s not worth thru-running even if you have the infrastructure because you have to arbitrarily pair the tails. (Not clear why this wouldn’t apply to all the other major cities around the world that thru-run service planned by people who know much more about travel demand than either of us, or for that matter to the subway. Sure some people still have to change trains but it still works much better than having everything dead-end in the middle.)
2. It’s not worth having infill stops at places like Elmhurst since they’ll get low ridership. (They get low ridership if fares are several times higher than the local transit fare, as has been traditional on the LIRR, but as my OP noted in most major cities you can ride inbound at such a station on a regional train for the same fare as the local subway/metro, even if the train started 100km away.)
3. There should be a regional rail tunnel across Lower Manhattan linking LIRR to NJT. (I think everybody here agrees on this? I think it’s Alon’s second regional rail construction priority after Gateway-with-alt-G most of which is supposedly happening anyway.)
4. The Fulton regional rail tunnel should be higher priority than the “alt G” extension of Gateway to Grand Central. (Eh, maybe? I think part of the reason Alon focuses on the Grand Central link is the hope that Gateway be built with provision for it rather than it necessarily needing to come before Fulton.)
5. The Fulton regional rail tunnel should be higher priority than thru-running most service at the existing Penn Station. (Thru-running on the existing infrastructure is so much cheaper that these don’t meaningfully trade off, see also point 1.)
6. The Fulton regional rail tunnel should have a giant cavern with 8+ tracks like East Side Access so all the NJT and LIRR trains can terminate there rather a two-track station with them running thru, because if they run thru you have to decide which tails to pair and that’s too confusing. (???)
7. Something else I didn’t think of.
Which of points 1-6 do you agree or disagree with?
This may come as shock to you but people who are getting off the train don’t care where it going. Blissfully unconcerned if it is terminating or continuing on. Or where it came from. Unless they need to know that to select the correct train. Believe it or not there are places where more than one kind of train can appear on the platform.
It’s unlikely to be arbitrary. They would make attempts to pair up low demand branches with low demand branches and give them short trains and pair high demand branches with high demand branches. And give them long trains. Origins and destinations except perhaps Jamaica and Newark would be …. diffuse..
There are nine colors on the the maps – on either side of Penn Station. It’s not going to be this tidy because there are branches that are busier and branches that have local and express service. 89 percent of the time where ever you want to go, other than perhaps Jamaica or Newark won’t be connected to your branch and you are going to have to change trains anyway. If the goal is facilitate travel between Jamaica and Newark people who want to do that don’t care about what is in Manhattan and can go through Brooklyn to do it.
And it’s likely to be higher than 89 percent of the time because you are on a branch that connects to the local that terminates short of your destination. It falls apart when you peer at the details.
Everybody wants an express ride from where they are to where they are going. If that happens nobody gets an express ride because the train is stopping at all the stations. Not stopping is the epitome of express ride. Not stopping at low demand locations makes the ride more express-y.
The people who aren’t clueless starry eyed railfans will use the M train or the R train. Because except for a few trips like an event at Madison Square Garden using the M train or the R train is faster. The same is true for most of Alon’s clueless commuter infill stations.
Yes there should be. Before there are pointless tunnels connecting Grand Central and Penn Station. You have to define goals. If the goal is to get New Jerseyans to Grand Central they don’t have to loiter around in Penn Station New York to do that. They can get an express ride by converting East Side Access into a through running shuttle to Newark. My preference would be every five minutes on today’s PATH tracks in Penn Station Newark and every ten at Broad Street Newark. …… and it would give them a second way to get between Newark and Jamaica though I doubt many people would use it because it would be slower.
Yes it should. I understand that all the trains do NOT have to stop at all the stations. The railfan fantasies of connecting Penn Station to Grand Central has something to do with the lower level. And gazing in awe at the platforms of Penn Station New York. That needs Dagny Taggart, Reardon metal and eventually abandoning the upper level. So that suburbanites can waste time viewing the platforms at Penn Station. I also understand that today, right now, if I was in Penn Station Newark and I wanted to go Madison Square Garden I could take a commuter train to Penn Station New York. If I wanted to go to the World Trade Center I could go through the turnstiles, on the same platform, and take a different train, a PATH train. I’ll be dead by the time this happens, I could cope with having a third option of taking yet a different train to Grand Central. Without stopping in Journal Square or anyplace else in Jersey City. Or Penn Station New York. Because I don’t give a flying fandango about any of them. I want to get to the East Side.
The railfan fantasy of running all of NJTransit trains to Metro North territory needs disemboweling Grand Central to give it an East Side Access duplicate. Do that and they, I’m sure I’ve mentioned this, they can’t run to Long Island. Not running to Long Island makes running through to Long Island very difficult.
Who said anything about terminating any thing downtown? Depends on how many services get packed into it. Half of East Side Access if it’s four stubby local branches in New Jersey connecting to four stubby local branches in eastern Queens. Full blown East Side Access with cross platform transfers for some same direction trips!! Transfers, I mentioned this earlier, if the train is running through to Grand Central it can’t simultaneously run through to Long Island.
I might have a solution to the conundrums.
When the 8th Ave. Express train is headed north to 207th Street call it RER A1. When it’s headed south to Lefferts Blvd, RER A2, Far Rockaway RER A2, Rockaway Park RER A3. The 8th Ave. Local can be Metro Line 1. When the 6th Ave Express is headed north to 205th Street it can be RER B1 and RER B2 when it’s going to Coney Island. The 6th Ave. local can can Metro Line 2. Etc. Yokels from the hinterlands will be even more confused than they are now.
The local to Croton can be S-bahn 1. The express to Poughkeepsie S-Bahn 2.
…. it’s not how long it is, it’s what you do with it…
and jourrney times will be reduced to an hour end-end?
Why would changing the name of the Wassaic Express to S-Bahn 43 make it faster? If you change the end of New Haven Express from Penn Station to Trenton the trip will be over two hours. Using the distances in the Wikipedia article on the Northeast Corridor it would go from 72 miles or 116 kilometers to 130 miles or 203 kilometers.
….. it’s not how long it is, it’s what you do with it.
I just looked up BART, America’s rapid transit system that runs like an S-Bahn. The Yellow Line from San Francisco airport to Antioch is 100km long, which is longer than any of those lines quoted above. Most of that is served by a train every 10 minutes off-peak. How unusual is this internationally?
And what are some ways to make BART, especially the Yellow Line more useful for urban passengers?
Brighton-Bedford is 160km 😜
Alon gave length from the city centre. End to end only one of Paris’s 5 RER lines is less than 100km, and that is RER-E which is about to be hugely extended to the west (taking over one of A’s branches joined to the centre by an 8km tunnel under western Paris). RER-D is actually 190km.
The answer to your question is what BART wanted 6 decades ago: go all the way to San Jose.