Philadelphia and High-Speed Rail Bypasses (Hoisted from Social Media)

I’d like to discuss a bypass of Philadelphia, as a followup from my previous post, about high-speed rail and passenger traffic density. To be clear, this is not a bypass on Northeast Corridor trains: every train between New York and Washington must continue to stop in Philadelphia at 30th Street Station or, if an in my opinion unadvised Center City tunnel is built, within the tunnel in Center City. Rather, this is about trains between New York and points west of Philadelphia, including Harrisburg, Pittsburgh, and the entire Midwest. Whether the bypass makes sense depends on traffic, and so it’s an example of a good investment for later, but only after more of the network is built. This has analogs in Germany as well, with a number of important cities whose train stations are terminals (Frankfurt, Leipzig) or de facto terminals (Cologne, where nearly all traffic goes east, not west).

Philadelphia and Zoo Junction

Philadelphia historically has three mainlines on the Pennsylvania Railroad, going to north to New York, south to Washington, and west to Harrisburg and Pittsburgh. The first two together form the southern half of the Northeast Corridor; the third is locally called the Main Line, as it was the PRR’s first line.

Trains can run through from New York to Washington or from Harrisburg to Washington. The triangle junction northwest of the station, Zoo Junction, permits trains from New York to run through to Harrisburg and points west, but they then have to skip Philadelphia. Historically, the fastest PRR trains did this, serving the city at North Philadelphia with a connection to the subway, but this was in the context of overnight trains of many classes. Today’s Keystone trains between New York and Harrisburg do no such thing: they go from New York to Philadelphia, reverse direction, and then go onward to Harrisburg. This is a good practice in the current situation – the Keystones run less than hourly, and skipping Philadelphia would split frequencies between New York and Philadelphia to the point of making the service much less useful.

When should trains skip Philadelphia?

The advantage of skipping Philadelphia are that trains from New York to Harrisburg (and points west) do not have to reverse direction and are therefore faster. On the margin, it’s also beneficial for passengers to face forward the entire trip (as is typical on American and Japanese intercity trains, but not European ones). The disadvantage is that it means trains from Harrisburg can serve New York or Philadelphia but not both, cutting frequency to each East Coast destination. The effect on reliability and capacity is unclear – at very high throughput, having more complex track sharing arrangements reduces reliability, but then having more express trains that do not make the same stop on the same line past New York and Newark does allow trains to be scheduled closer to each other.

The relative sizes of New York, Philadelphia, and Washington are such that traffic from Harrisburg is split fairly evenly between New York on the other hand and Philadelphia and Washington on the other hand. So this really means halving frequency to each of New York and Philadelphia; Washington gets more service with split service, since if trains keep reversing direction, there shouldn’t be direct Washington-Harrisburg trains and instead passengers should transfer at 30th Street.

The impact of frequency is really about the headway relative to the trip time. Half-hourly frequencies are unconscionable for urban rail and very convenient for long-distance intercity rail. The headway should be much less than the one-way trip time, ideally less than half the time: for reference, the average unlinked New York City Subway trip was 13 minutes in 2019, and those 10- and 12-minute off-peak frequencies were a chore – six-minute frequencies are better for this.

The current trip time is around 1:20 New York-Philadelphia and 1:50 Philadelphia-Harrisburg, and there are 14 roundtrips to Harrisburg a day, for slightly worse than hourly service. It takes 10 minutes to reverse direction at 30th Street, plus around five minutes of low-speed running in the station throat. Cutting frequency in half to a train every two hours would effectively add an hour to what is a less than a two-hour trip to Philadelphia, even net of the shorter trip time, making it less viable. It would eat into ridership to New York as well as the headway rose well above half the end-to-end trip, and much more than that for intermediate trips to points such as Trenton and Newark. Thus, the current practice of reversing direction is good and should continue, as is common at German terminals.

What about high-speed rail?

The presence of a high-speed rail network has two opposed effects on the question of Philadelphia. On the one hand, shorter end-to-end trip times make high frequencies even more important, making the case for skipping Philadelphia even weaker. In practice, high speeds also entail speeding up trains through station throats and improving operations to the point that trains can change directions much faster (in Germany it’s about four minutes), which weakens the case for skipping Philadelphia as well if the impact is reduced from 15 minutes to perhaps seven. On the other hand, heavier traffic means that the base frequency becomes much higher, so that cutting it in half is less onerous and the case for skipping Philadelphia strengthens. Already, a handful of express trains in Germany skip Leipzig on their way between Berlin and Munich, and as intercity traffic grows, it is expected that more trains will so split, with an hourly train skipping Leipzig and another serving it.

With high-speed rail, New York-Philadelphia trip times fall to about 45 minutes in the example route I drew for a post from 2020. I have not done such detailed work outside the Northeast Corridor, and am going to assume a uniform average speed of 240 km/h in the Northeast (which is common in France and Spain) and 270 km/h in the flatter Midwest (which is about the fastest in Europe and is common in China). This means trip times out of New York, including the reversal at 30th Street, are approximately as follows:

Philadelphia: 0:45
Harrisburg: 1:30
Pittsburgh: 2:40
Cleveland: 3:15
Toledo: 3:55
Detroit: 4:20
Chicago: 5:20

Out of both New York and Philadelphia, my gravity model predicts that the strongest connection among these cities is by Pittsburgh, then Cleveland, then Chicago, then Detroit, then Harrisburg. So it’s best to balance the frequency around the trip time to Pittsburgh or perhaps Cleveland. In this case, even hourly trains are not too bad, and half-hourly trains are practically show-up-and-go frequency. The model also predicts that if trains only run on the Northeast Corridor and as far as Pittsburgh then traffic fills about two hourly trains; in that case, without the weight of longer trips, the frequency impact of skipping Philadelphia and having one hourly train run to New York and Boston and another to Philadelphia and Washington is likely higher than the benefit of reducing trip times on New York-Harrisburg by about seven minutes.

In contrast, the more of the network is built out, the higher the base frequency is. With the Northeast Corridor, the spine going beyond Pittsburgh to Detroit and Chicago, a line through Upstate New York (carrying Boston-Cleveland traffic), and perhaps a line through the South from Washington to the Piedmont and beyond, traffic rises to fill about six trains per hour per the model. Skipping Philadelphia on New York-Pittsburgh trains cuts frequency from every 10 minutes to every 20 minutes, which is largely imperceptible, and adds direct service from Pittsburgh and the Midwest to Washington.

Building a longer bypass

So far, we’ve discussed using Zoo Junction. But if there’s sufficient traffic that skipping Philadelphia shouldn’t be an onerous imposition, it’s possible to speed up New York-Harrisburg trains further. There’s a freight bypass from Trenton to Paoli, roughly following I-276; a bypass using partly that right-of-way and, where it curves, that of the freeway, would require about 70 km of high-speed rail construction, for maybe $2 billion. This would cut about 15 km from the trip via 30th Street or 10 km via the Zoo Junction bypass, but the tracks in the city are slow even with extensive work. I believe this should cut another seven or eight minutes from the trip time, for a total of 15 minutes relative to stopping in Philadelphia.

I’m not going to model the benefits of this bypass. The model can spit out an answer, which is around $120 million a year in additional revenue from faster trips relative to not skipping Philadelphia, without netting out the impact of frequency, or around $60 million relative to skipping via Zoo, for a 3% financial ROI; the ROI grows if one includes more lines in the network, but by very little (the Cleveland-Cincinnati corridor adds maybe 0.5% ROI). But this figure has a large error bar and I’m not comfortable using a gravity model for second-order decisions like this.


  1. SCC

    Unfortunately, your analysis doesn’t take in account the significant demand from Center City Philadelphia to Harrisburg, the state capital. There might be an argument for shifting the Center City traffic to the North Philadelphia station via the Broad St subway, but too many Center City riders would complain about such a service change.

    • Alon Levy

      It absolutely takes it into account, it just throws it into the average with traffic from Philadelphia to farther away but much larger Pittsburgh.

    • Ben She

      There might have been Harrisburg-PHL demand pre-pandemic, but since 2020 the Keystone trains have done abysmally, lagging behind every other state-supported corridor. When before there was only a $5M monthly operating loss, it’s now ballooned to $40M, as much as the worst long-distance routes lose.

  2. adirondacker12800

    the fastest PRR trains did this, serving the city at North Philadelphia with a connection to the subway, but this was in the context of overnight trains of many classes.
    The subway wasn’t there until 1928 and is quite a hike. There were daytime trains too. Lots and lots of them. Which they would change to unless they picked a train that was going to Broad Street and later 30th Street and Suburban.

  3. UrbanUnPlanner

    Here’s the rub: it’s *not necessary* for trains from New York to Harrisburg and points west to bypass Philadelphia in order to get rid of the pesky turnaround at 30th St! Instead, there looks to be enough space on the north side of North Philadelphia station to bring a flyover up (using some space left by abandoned tracks — it’d require reworking a pedestrian overpass, but that’s fine) and over the NEC to join the Reading Main Line commuter tracks that cross over the NEC on a bridge just west (timetable south) of the station. From there, a New York-Harrisburg/points-west train would roll through Suburban Station and then use the Center City Commuter Connection to get to the upper level platforms at 30th St, where it can stop before continuing onward to the north and west to merge back in more or less at Zoo.

    • adirondacker12800

      The former Pennsylvania tracks are elevated over the street and the former Reading tracks are in a trench under the street. You would have to tear down wide swaths of North Philadelphia to take a longer route through 30th Street.

    • Ben She

      With the correction that the Reading main line crosses under the NEC (not over), greatly complicating matters, it’s really not apparent to non-Philadelphians how slow the CCCT is geometrically designed, how much that lengthy diversion adds even more time than improved reversals from 30th, and how Amtrak slotting directly interferes with SEPTA’s own goals to get at least 5 Regional Rail lines to 15 min all-day frequency. Far easier to secure dedicated higher-speed Amtrak tracks through Zoo.

      • adirondacker12800

        A flyover for the Chestnut Hill West line would disentangle things. There are extensive threads on the railfan sites about better “balancing” SEPTA commuter rail and perhaps sending one or two of the former Reading lines to North Philadelphia, along with the Chestnut Hill West line, instead of through North Broad. ( Counter-clockwise around the loop instead of clockwise. ) Cheapest, least construction option would be the Norristown-Manaunk line.
        A very quick glance at satellite images between North Philadelphia and Zoo there are five tracks and there used to be a lot more. They can figure out what to do in 2090 when Amtrak has gotten New York to D.C. down to two hours.

          • adirondacker12800

            Barely a mention of level boarding. Level boarding saves a lot of time at each stop which makes the trip a lot faster. People who own cars take the train when taking the train is faster than driving and finding parking. Running slow trains every half hour isn’t going to attract them. Running slow trains every 15 minutes isn’t either.

          • Richard Mlynarik

            Sorry about this link. Anyway, “own goals” in the football (soccer) sense. Pathetic pun.

            Ever single encounter I’ve ever had with SEPTA in my life has been “we hate you and we want you to go away and, preferably, die.” Just a nightmare of user hostility and decrepitude and waste and wasted opportunity and decay.

            USA USA USA!

          • Nilo

            Richard part of the problem with changing things from decrepitude is you have to actually plan to change them before the change happens. The public and it seems the agency wants rapid transit (including level boarding) on a core portion of the network within the next 10-ish years. Maybe they’ll faceplant but actually wanting to make things better is very different from how the agency historically operated.

    • Alon Levy

      I think that might not actually save time over reversing at 30th Street – the SEPTA Main Line is pretty slow and the CCCC is even slower. It does have benefits in getting people closer to Center City destinations and in avoiding making at least half the train face backward for part of the trip, but then the former benefits must be weighed against both slowing down New York-Washington through-trips and the impact on regional rail.

      • adirondacker12800

        It’s never going to happen because you’d have to tear down wide swaths of North Philadelphia.

      • UrbanUnPlanner

        Apologies — I did not realize the CCCC was that geometrically challenged!

  4. adirondacker12800

    There’s a freight bypass from Trenton to Paoli,

    That just moves the congestion from North Philadelphia to Morrisville, just across the river from Trenton.
    If Philadelphia-New York is getting congested, the goal would be to keep trains off it.

    A bypass of Philadelphia and Wilmington, in the general vicinity of the New Jersey Turnpike/I-295 would divert the most people and speed the most trips. Just like the New Jersey Turnpike/I-295 diverts through road traffic around Philadelphia and Wilmington today.

      • adirondacker12800

        Silly me. when you said Trenton I assumed you meant……..Trenton.
        The Trenton Cutoff still goes to Trenton. Wikipedia says Norfolk Southern uses it between Conrail’s Morrisville yard and Glenlock which is just west of Paoli. If you want to finagle something where trains use the former Central of New Jersey/Reading between Newark and Woodbourne, where the Trenton Cutoff and SEPTA’s West Trenton line cross, that doesn’t involve Trenton.

          • adirondacker12800

            They have been skipping Trenton forever. If a train is not-stopping in Trenton it’s still on the tracks in Trenton. If you want to use the former CNJ/Reading tracks, those clever clever Philadelphians, don’t call the terminal station Trenton. Because they aren’t in Trenton. They are in Ewing.

    • dlwynter

      A maybe naive question, but if we’re going to bypass Philadelphia, especially for New York-Midwest trains, might it be worth cutting through Allentown to Harrisburg instead of just from Trenton to Paoli? This bypass would be only 3.5x the length of the Trenton-Paoli freight bypass, would closely follow the I-78, and would potentially pick up between New York and Allentown, which has a moderately sized metro area (865k according to wikipedia). This would also save ~30mi relative to cutting through/around Philadelphia.

      • adirondacker12800

        It depends on what your goal is. If your goal is to keep traffic off the line through Trenton, the way to divert the most traffic is a super-express skipping Delaware, Pennsylvania and New Jersey, roughly along the New Jersey Turnpike/I-295. In 2075 when NJTransit gets around to electrifying between Newark and West Trenton there can be a train or two an hour along that route. If your goal is to speed up Midwest to New York it’s Harrisburg, Reading, Allentown. That would be very expensive because it’s all mountain in western New Jersey all the way to Harrisburg.
        20-ish miles if it diverts to Reading.
        Very expensive and the best Reading can hope for is once every two hour extension of SEPTA service to Philadelphia and Allentown once or twice an hour extension of SEPTA to Philadelphia and once or twice an hour extension of NJTransit to New York. Maybe a once an hour bus to Harrisburg for places west of Harrisburg. In 2133 when there is high speed rail to Pittsburgh, Ohio and Detroit.

        • John Marquette

          Locals in the Lehigh Valley (Allentown and Bethlehem) consider Philadelphia an afterthought. The desire is for New York trains. The ROW from just north of Quakertown to Bethlehem has been converted to a great trail, and McMansions have been built up along it. That is so unlikely to change. But Harrisburg-Reading-Allentown-Raritan Valley-NYP – that could happen.

          • bensh3

            It’s the Lehigh Valley’s loss that Philadelphia connectivity, linking the state’s 1st and 3rd-largest metros is so deprioritized. Meanwhile regional planning commissions for LV and Philly are still adamant about widening the whole Northeast Extension up to US-22 for untold millions of $$. McMansions notwithstanding, SEPTA negotiating with a rail trail is far easier than the current battle with NS over Reading service.

  5. Diego

    I think the main worry on Twitter was that building the infrastructure to bypass Philly would lock in a bad operating pattern. There are plenty such examples by SNCF. But this post makes clear that you can change the service in an incremental way: first reversing, then taking the other branch at Zoo (maybe stopping at North Philly), then maybe building a greenfield bypass. You only need to move to the next stage if the ridership justifies it and service levels are high on all routes.

    Anyway, seems pretty clear to me that cutting NYMidwest trips by 15 mins is worth more than reducing headways from Philly by 15 min. Ridership from NY will be higher, and a 15 min headway cut is only a 15 min travel cut in the worst case scenario.

  6. Phake Nick

    I think this is worthless to discuss until NYC to Pittsburg high speed rail actually exists, which probably won’t happen within this century.

    But if this do happens, in case the bypass is used instead of following some newer and shorter right of way that skip the entire city altogether, then wouldn’t it make sense to build a new station somewhere along the bypass route so that people on the non-reversing trains can still deboard and reach Philadelphia?

      • Eric2

        Unless you were referring to the Trenton Cutoff (or similar). In which case, I imagine the best station location would be King of Prussia. Which hopefully gets a regional rail branch at some point (not the stupid Norristown purple line).

    • dlwynter

      Why do you think there’s such a low chance that a high speed NYC-Pittsburgh line (or Philly-Pittsburgh line) could be built? If the Appalachians are the main obstacle, it’s not unheard of to have ~50mi of tunnels, like the Bologna-Florence line in Italy. Though of course there are always political issues with these kinds of infrastructure projects..

      • adirondacker12800

        Because we’ve been waiting almost 60 years for high speed rail between Philadelphia and New York?

      • Phake Nick

        Because no known process or group trying to fund this thing.

        If the finance can sort out then 8-20 years this thing should be able to be built but I don’t see how the finance side can be sort out.

  7. Philly Cheesesteak

    In favor of trains stopping at 30th Street. Is it possible to construct a second level of tracks from the Zoo interlocking, as a new upper level of tracks that feed into the upper level of 30th Street Station? That way, Amtrak trains could use this upper level bypass and zoom in and zoom out. Surely the crewing issue could be solved somehow to ameliorate the 10-15 minute stop to reverse direction.
    NY-Washington trains continue to use the lower level platforms.
    Septa trains to/from the Main Line now use the lower level platforms (?).
    Trains to and from Harrisburg and the Midwest now use the upper level platforms.
    Other Septa trains use the upper level platforms. From what I remember, the upper level is underused and there would be space for Amtrak.
    Fringe benefit: easy access to Suburban Station for future extension.

    • Matthew Hutton

      One of the reasons that the Japanese can build their stations with a small number of platforms is that they have many more staff to clean the trains.

      If those cleaning staff have a total cost of employment of £30/hour for 16 hours a day with 16 staff per train and 6 platforms then that costs you only £16m/year – and it costs you something to clean the trains anyway so even with overstaffing its almost certainly cheaper to do that than to build a massive new station as it’d take 25 years to spend £1bn on cleaning staff – plus good blue collar unionised jobs are popular with the electorate.

      In terms of Philadelphia it is almost certainly cheaper to overstaff the trains and have new drivers ready to turn the train around within 1-2 minutes than it is to build a massive new station complex or a massive tunnelling project to avoid turning the trains around.

      • Matthew Hutton

        I don’t think so. But it’s the same deal. Perhaps it costs an extra $40/train to swap the drivers over and turn it round. Then if you’re running 6 trains per hour, 16 hours a day 365 days a year that costs you $1.5m/year.

        And sure there’s a benefit for not doubling back on 2km of track, but we’re probably arguing over a minute or something assuming you can move through the station throat at a good pace.

        No way it’s worth a billion in infrastructure to avoid that.

        • adirondacker12800

          When they change ends on a train there are a lot of things that have to be checked and tested. It takes time.

          Tracks and platforms aren’t a problem. Not for the next few decades anyway. There are four tracks from the west, four tracks from the north, weird peculiar things go on in the Zoo interlocking. There are four tracks oriented east/west and four tracks oriented north/south at 30th street. In normal service SEPTA trains are on the east/west tracks. Amtrak and NJTransit are on the north/south tracks. Someone needs to draw an abstracted drawing of it. Very abstract because weird and peculiar things happen in Zoo interlocking.

          • Matthew Hutton

            That’s fair in general, however in this case in exchange for 5-10 minutes you’re gaining a stop in the centre of a large city – really the largest between the New York metro area and Chicago.

          • adirondacker12800

            It’s not 5 minutes it’s more like a half hour which might be possible to speed up. To 15 or 20. North Philadelphia isn’t 10 blocks away from 30th Street. It’s five miles away through a complicated, slow interlocking. It takes SEPTA between 10 and 15 minutes to get between 30th Street and North Philadelphia.

            This ain’t whatever wide place in the road you live in. Philadelphia is the country’s 7th largest MSA. It’s the same size as Washington DC’s. which is number 6. Or Atlanta at 8 or Miami at 9.
            The Harrisburg CSA and the Lancaster MSA are the same size as metro Providence RI. Throw in the suburban Philadelphia along the Main line it’s the same size as the San Jose CA MSA or Cleveland’s. If Amtrak had the equipment there could be TWO different trains. One to Washington DC via 30th Street and one to New York that may or may not stop in North Philadelphia. If they had the equipment they could run the Regionals from Springfield THROOOOGH to Washington and skim off even more of the Philadelphia-DC passengers and Philadelphia-Baltimore. East Side Access is supposed to open next month. If they had the equipment there would be capacity through Penn Station New York to do that.

          • Matthew Hutton

            30th street is 2km from a corner you can do at 120km/h. Alon can I’m sure give proper numbers but at worst it’s 1 minute slower than some other random stop in Philidelphia. Then you need perhaps as many as four minutes to turn the train around and go back the other way. This is done routinely in the UK – although I believe Alon says it is done faster in other countries?

            On top of that on the way out I believe it merely costs you 2km at 300km/h because you have to do the initial acceleration somewhere and the route alignment to the West looks pretty straight. So that would be perhaps 30 seconds more?

            And to be honest I’d expect you’d want to stop at 30th street for 2 minutes anyway so the total excess time should be like 3.5-4 minutes or maybe less?

            Now sure as others are suggesting perhaps Baltimore is better to cut up – which seems like it makes this whole thing redundant.

          • adirondacker12800

            Philadelphia is the country’s 7th largest metro area and New York is the country’s biggest. There will be enough demand to have DIFFERENT trains.

    • bensh3

      And you’re getting your information from who? Who says the upper level is underused? Why cut off SEPTA trains from through-running? New tracks that go east-west instead of north-south are still stub-end, and going to Suburban is the same diversion of Broad St Station the PRR wanted to fix with 30th.

      • Eric2

        Honestly, ~17tph at the rush hour peak spread over 6 tracks is ridiculously underused. Yes this should be increased, but in our lifetimes it won’t be increased to the point where 6 tracks are needed. (For one thing, the continuation of the tunnel to Center City only has 4 tracks)

        • adirondacker12800

          There are only four tracks between 30th Street and Suburban too. Suburban has five islands. Four terminal tracks and two of the through tracks are Spanish Solution with platforms on both sides of the train.

          • Matthew Hutton

            32tph per direction can be handled with 6 tracks with ease and can be handled with 4 tracks with good operations.

            Thameslink in London which is regional rail does up to 18tph at peak and 14tph off peak with two tracks. It is supposed to be able to do 24tph at peak, but they haven’t ever managed to.

          • bensh3

            Writing this many words for what is less than 500m of six-track segment is very amusing. But when looking at the actual layout, the four-track trunk immediately fans out into three double-track branches past 30th. Consolidation would not only remove the ability to schedule timed overtakes at platforms, but it’s geometrically impossible with the elevated High Line freight bypass piers in the way, and center tracks depressed relative to the outer ones. So there’s no logical way to give Amtrak a dedicated stub-end platform.

          • adirondacker12800

            There are 6 branches east of Suburban and 7 west of Suburban. Trains to Trenton head west and trains to West Trenton head east.

            East of Suburban are:
            Chestnut Hill East
            West Trenton

            West of Suburban are:
            Chestnut Hill West
            Wawa, formerly Media/Elwyn

            If they do clever things like the express from Doylestown becomes the express to Thorndale and the local from Fox Chase becomes the local to Cynwyd, it’s four lines bouncing back and forth through Jefferson. 16 an hour.

            I don’t care about the details because they aren’t going to be running frequent service until it’s faster than driving. At the rate SEPTA does things perhaps 2060. People will have different proposals between now and then.

          • adirondacker12800

            Fox Chase is east of Suburban… for the sixth branch.

  8. spencepatrickj

    Baltimore is 77 miles west of Philadelphia but only 45 miles south. That means a line from Philadelphia-Lancaster-Harrisburg-Pittsburgh is only 20 miles shorter (and perhaps ten minutes faster) than a line from Philadelphia-Baltimore-Hagerstown-Pittsburgh. But if the NEC is already upgraded from Philadelphia to Baltimore, that means a route through Baltimore requires 60 fewer miles of new-build high speed rail.

    I think because Philadelphia and Pittsburgh are in the same state, network planners don’t think to cross the state line. This is an irrational mental shortcut. Absent that line, most people would minimize track mileage by drawing a tri-point network between Washington, New York, and Pittsburg that converges in Baltimore.

    Is saving ten minutes on New York-Midwest trips and slightly cutting journey times on New York-Harrisburg worth the cost of building an extra 60 miles of high-speed rail? Bear in mind that Philadelphia-Chicago runs would almost certainly skip Lancaster and Harrisburg, so from the perspective of planning timetables, routing high speed trains to the Midwest through Baltimore doesn’t require the creation of *additional* New York-Harrisburg runs–it just keeps them on the current Keystone Corridor.

    An analogue to this might be if Columbus and Indianapolis were in the same state but Cincinnati fell just south of the state line in Kentucky. Planners might instinctually draw a line directly from Indianapolis to Columbus while leaving Cincinnati on a largely parallel branch from Columbus to Louisville. Obviously, doing this would reduce connectivity, increase construction costs, and reduce train utilization of each track mile. Is defaulting to the Keystone Corridor any different?

    • Eric2

      This does seem like the best solution for Philadelphia-Pittsburgh. It does mean sketching a ROW through the Baltimore suburbs which doesn’t look easy. Maybe the best solution would be to bypass Baltimore with a greenfield ROW from roughly Elkton MD to Hagerstown MD paralleling the state boundary. There may be political difficulties though – Pennsylvania might object to Harrisburg not getting a stop, and Baltimore might object to not getting a stop (though maybe you could give them a beetfield stop north of the city, plus the option to transfer in DC/Philly for center city access).

      • Eric2

        Washington is much further out of the way (to the south). Also in Washington you’d have the same reversing problem as in Philadelphia.

    • bensh3

      Rail mileage isn’t uniformly the same everywhere, where you build is just as important as how much you build. Between Baltimore-Hagerstown, the Catoctin Formation presents a significant obstacle, in addition to the generally hillier terrain of Northern Maryland. An alignment along I-70 may or may not be feasible. To avoid all this it might be easiest to branch off straight from Wilmington station (a tight curve anyway) and rejoin the Keystone Corridor at Atglen, where 175 kmh and upgradeable track picks up. Then from Harrisburg, follow I-76 PA Turnpike through the Cumberland Valley to rejoin the tunneling.

      • Eric2

        There are several passes through the Catoctin Formation that aren’t bad at all, and once past it you’re in what I think is a better position for crossing the Appalachians.

    • Alon Levy

      In theory, sure.

      In practice, Baltimore is a lot harder to get to than Philadelphia. Philadelphia has the Main Line as a good approach to use before transitioning to a greenfield corridor, but north of Baltimore there are no good ROWs and the terrain is such that something like 8 km of tunnel are required.

      • adirondacker12800

        Not even in theory. There is more demand towards Philadelphia than there is towards Baltimore. Game over.

        Road distances being similar to what rail distances could be Pittsburgh-Washington-Philadelphia is 143 miles/230 km longer than Pittsburgh-Harrisburg-Philadelphia. It would add an hour of travel time to the high demand markets. If you don’t want to spend a gazillion dollars so that extra wide place along the road that is Hagerstown is along a high speed rail route Pittsburgh-Harrisburg-Lancaster-Perryville-DC is …… 143 miles longer…. 242 miles/389 km versus 361/580. It would still be under three hours and under three beats flying. Lancaster to Perryville is 40 miles/65km.

        • spencepatrickj

          Sure, but I never said anything about DC. The bulk of that distance differential is from Frederick down to DC and back up to Baltimore. Cut across I-70 and it vanishes. Obviously, there’s more demand towards Philly/NY than Baltimore/DC (guessing about 3x). However, this is not an issue of absolute demand but optimization. Is adding 10 minutes of travel time to ~30 million people mitigated by cutting 60 minutes of travel time to ~10 million people. Most gravity models would say yes. And this becomes more than justified if it reduces construction costs.

          • adirondacker12800

            It’s not adding 10 minutes of travel time no matter how hard you click your heels.

          • spencepatrickj

            Philadelphia-Pittsburgh via Baltimore is 20 miles longer than via Harrisburg. That’s 10 minutes. Prove me wrong.

          • adirondacker12800

            It’s 100-ish miles from Baltimore to Philadelphia. 100 miles at an average speed of 150 is 40 minutes.
            To make it 10 the average speed would have to be 600.

          • spencepatrickj

            But the distance from Baltimore to Pittsburgh is shorter than the distance from Philadelphia to Pittsburgh. This really isn’t that complicated.

          • adirondacker12800

            People in Pittsburgh who want to go to Philadelphia are deeply deeply uninterested in the attractions of Baltimore. Or people in Pittsburgh who want to go to New York or New England. I also suspect when they have some business to conduct with their state government they are bright enough to figure out to attempt that in Harrisburg, not Annapolis.

          • adirondacker12800

            …..if the point is to just mindlessly take high speed rail trips, Cleveland is only 133 miles from Pittsburgh.

          • spencepatrickj

            There’s nothing about crossing the state line twice that makes getting to Philadelphia and New York meaningfully more difficult. That’s the point. You can save money by building the shorter line to Baltimore. Not to mention the dividends it pays for trips to Washington, which almost certainly has the second highest demand on the NEC. And Pittsburgh-Cleveland is obviously a link worth building. Are you being deliberately obtuse?

          • adirondacker12800

            Why does that matter to people who want to go to Philadelphia? New York or New England? Or people who start out there? They don’t want to go to Baltimore.

          • spencepatrickj

            Because it saves money and barely costs them travel time. And because they’re about 75% of passengers, not 100%. And the concentrated benefits to the 25% outweigh the dispersed costs to the 75%. Why is it so hard for you to understand cost-benefit optimization?

          • adirondacker12800

            It doesn’t save money because Pennsylvanians are going to want high speed rail between Harrisburg and Philadelphia. And New Jerseyans, New Yorkers and New Englanders. There are a lottttttttttt of people, in Pennsylvania, west of the 40th Street Station of the Market-Frankford line, in Philadelphia.

          • spencepatrickj

            Sure. And they should be served. Pittsburgh via a Philly-Pittsburgh line that incidentally crosses into Maryland and Lancaster/Harrisburg via the conventional Keystone Corridor. I could just as easily gaslight you as to why you’re so obsessed with running a high-speed line through Lancaster and ignoring a much larger city to its south.

          • adirondacker12800

            How are they supposed to get from Harrisburg to the high speed line that goes to the center of the universe in Baltimore from Pittsburgh? Bring their collapsible personal helicopters along as a carry-on?

      • spencepatrickj

        I don’t think that’s entirely true. Maybe 2.8 km of tunnel from the NEC to the terminus of I-70 and another 1.1 km under Gathland State Park. Maybe a bit more to get under the US-340/US-15 junction, but I think that can be a cutting. That’s probably more than made up for by the reduced distance across the Appalachians–and it certainly *reduces* tunneling if the ROW can be laced along I-70 and the Potomac between Big Pool and Hancock.

    • SCC

      The state effect is actually REAL. For instance, San Francisco and Phoenix are both roughly the same distance as the crow flies from Los Angeles – both cities are about 350 miles from LA. Metro Phoenix (4.9m) has about 7% more population than metro San Francisco (4.6m). Plus, between Phoenix and LA is another similarly sized metro, Riverside-San Bernardino (4.7m). Yet the LA-to-SF travel demand corridor is much stronger than the LA to Phoenix travel demand corridor, so much so that it is obvious that high-speed rail from SF to LA is more economically important than LA to Phoenix. Why is that? It’s not a coincidence that SF and LA are in the same state.

      • spencepatrickj

        Because the Bay Area has a much larger GDP, is more of a tourist destination, and you have to include San Jose. Vegas and Phoenix also have about equal travel to LA, but neither is in California. Why? Tourism.

        • SCC

          According to the Bureau of Transportation Statistics, LAX to Las Vegas air passenger volume is higher than LAX to Phoenix passenger volume, and in fact, LAX to Las Vegas air passenger volume is higher than even LAX to SF. LAX to Las Vegas is actually the second highest volume destination from LAX next to LAX to JFK. (LAX to EWR is counted separately, and is the 8th top destination from LAX between Sept 2021 and Aug 2022.) There’s clearly higher travel demand from LAX to Las Vegas than LAX to Phoenix, even though both are in different states, and even though Las Vegas metro population is less than half the size of Phoenix and less than half the size of SF. Las Vegas metro GDP is also less than half the size of Phoenix’s GDP and about a fifth of the size of SF’s GDP. Geographically, Las Vegas is about 40 miles from the California border and about 230 miles from Los Angeles. From all that noise, how do YOU tease out that intrastate travel demand is not a significant factor of travel demand between any two city pairs within the same state or between nearby states, in this case between Los Angeles and nearby cities?

          Going back to the original example: New York is a similar distance from Philadelphia as London to Birmingham, with Liverpool beyond Birmingham a similar distance to Philadelphia to Baltimore. Washington is about as far from Baltimore as Manchester is from Liverpool. Dublin is a similar distance to London as Pittsburgh is to New York, give or take a couple dozen miles. If you were planning a high-speed rail line between London and Dublin, would you run the line London-Birmingham-Liverpool-Dublin, or London-Birmingham-Manchester-Dublin, given that Manchester has a larger population than Liverpool? Or would you run the line London-Birmingham-Chester-Dublin, which is even shorter than the other options, but will generate less demand?

          • adirondacker12800

            The snorkels, for the trains to and from Dublin, would be too long.

          • spencepatrickj

            My point is more that this is multifactoral, and I don’t think the state line is the clear explanatory factor the travel discrepancy on LA-SF and LA-Phoenix.

            Anyway, I would absolutely opt for London-Birmingham-Liverpool-Dublin, to whatever extent an Irish Sea tunnel is justifiable, which I suppose I would given my Baltimore preference.

          • Alon Levy

            In Britain, the infrastructure the exact opposite of that of the Northeastern US in that the routes that go through the major intermediate cities are bad for through-service whereas there are excellent bypasses (like the Trent Valley Line); in the Northeast, bypassing New York or Baltimore requires more tunneling than building Gateway and the B&P replacement, and bypassing Philadelphia is possible in an arc from New York to Harrisburg but not in one from New York to Wilmington or Baltimore. This is why HS2 puts the intermediate cities on branches without through-service; they figure that the expected frequency is so high that it would be okay, and that’s not the main design problem of HS2 (try the tunnels through the Chilterns). So in practice, London-Dublin HSR would go London-Crewe-Holyhead-tunnel-Dublin.

            By the way, Adi, the Holyhead-Dublin tunnel isn’t 100% crayon. The British government was seriously mulling it last year, so, given who the prime minister was, only about 80% crayon.

  9. adirondacker12800

    Politicians commission studies of stuff that is never going to be built, all the time. They go in the dusty archives along with the studies THE SAME POLITICIANS commissioned ten years earlier. Along with the ones from 20 years ago, 30 years ago, 40 years ago, 50 years ago. ….New Jersey and the railroads hired one of the usual suspects to examine the problem of commuting to Manhattan. They concluded rail is the best idea. It was released in 1959.

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