High-Speed Rail Should Serve Providence
The most straightforward part of constructing greenfield tracks for high-speed rail on the Northeast Corridor is east of New Haven. There are good legacy lines to hook into, and good Interstate corridors to follow when the legacy lines are too curvy. It’s also the segment with the biggest variation in alignment options, which boil down to going through Hartford and going through Providence. Both the Penn design proposal and the Amtrak proposal go through Hartford and avoid Providence, and this is a bad idea, for both costs and benefits reasons.
See here for a very early and rough draft of my HSR map, which goes through Providence; there are significant issues with this map west of New Haven, but it’s fairly accurate east of Haven. It uses I-95 between New Haven and the state line, and transitions to the legacy line around Kingston; Hartford would be served on the legacy line, which would be electrified. I have not seen detailed drawings of Amtrak’s proposal, but here is the detailed Penn design map, going through Hartford: the idea is to use a combination of I-91 and a heavily upgraded legacy line, and then transition to I-84 in Hartford and then I-90, while retaining the Shore Line for slower service to Providence. The latter option turns out to be inferior, essentially because full HSR is easier to build through Providence whereas a medium-speed branch is easier to build to Hartford.
First, the cost side. Because the portions of the Shore Line used by the Providence option are straight and already built to high standards, minimal upgrade work is required there. The bulk of the cost would be constructing high-speed track along a mostly flat, not very developed right-of-way, with two and a half painful segments (New London, the cutoff east of New Haven, and the Connecticut River crossing as the half). East of New London the median is available, cutting costs further. All in all, this is 125 km of largely at-grade track, and about 60 km of cheap electrification to Hartford.
Going through Hartford is about equally hard. The New Haven-Springfield line is built to low-speed standards, with grade crossings and curves that are good for 200 km/h rather than 300. It avoids the river crossings of I-95, but I-84 and I-90 are a bit curvier and follow more rugged and urbanized terrain, and the urban segment through Hartford looks harder than that through and immediately east of New Haven. Per kilometer it could cost about the same, but 200 km of new track are required.
The costs by themselves are not a huge deal. The New York-New Haven segment requires new grade-separated junctions, multiple bypasses, and some urban tunneling. In contrast, mostly at-grade track costs $20 million per kilometer or not much more, so despite the large difference in length, the difference in cost is about $2.5 billion vs. $4 billion.
However, there’s also a constructability argument for I-95, which is that it can be done in segments more easily, using portions of the Shore Line before the full line opens. This could be useful if money were made available in very small chunks. The Hartford route could be done partly on an electrified Springfield line, but Hartford-Boston has to be done in one go.
But a bigger issue is that going through Providence has two advantages over going through Hartford without regards to costs. First, Providence is a larger city than Hartford: its metro area is about 20% larger than Hartford’s, and the central city is 40% larger and denser. Although the Hartford option passes near Worcester, there is no way to bring a station into Worcester itself without excessive tunneling; the Penn design plan puts the station at the edge of the built-up area, 7 kilometers from downtown Worcester. The Providence option passes through much smaller New London, but it can at least be served by a station that’s within the city, one km from the present station.
The other advantage is how to serve the city that does not get to be on the HSR mainline. The Springfield line is easy to upgrade, since it is straight enough for medium speed, and grade crossing protection good for about 180 km/h is relatively cheap. This would give Hartford very good service to New York – about half an hour to New Haven, and a little more than another half an hour to New York. The Shore Line in contrast is curvy and slow and already has a fair amount of superelevation and cant deficiency, making future upgrades much harder. Providence would still get better trip times than today coming from better rolling stock and higher speeds west of New Haven, but better trip times than about 1:45 to New York are only possible with trains with high degree of tilt, which tend to be a maintenance nightmare.
For the record, my original proposal above is from 2009, and I only accepted my current job at Brown in 2011. However, in the interest of full disclosure, by 2009 I already knew that Brown had one of the best departments in my field, whereas Hartford doesn’t have a research university of comparable quality. I don’t think it biased my choice – the idea of following the present alignments and serving present lines as much as possible appears elsewhere in the plan as well as in my regional rail proposals for New York and Boston – but then again nobody thinks their own choices are biased.
Pedestrian Observations 
I also figured that the way forward on high-speed rail in the Northeast would involve significant re-use of the existing corridor. Much of the improvement needs to come west of New Haven. There seems to be lots of speed restrictions in Metro-North territory. Despite going slow in plenty of segments leading up to Stamford, a regional I rode last week got to NYC 20 minutes early! There’s lots of room for improvement.
I enjoy riding along the Shoreline but it is rather slow. Using I-95 like this is clever, though I’m not sure how easy it is to add tracks to the divided “Gold Star Memorial Bridge” near Old Saybrook. At least it avoids the whole problem of attempting to grade separate the existing New London station, which is a mess.
Soooo, having done this sort of analysis… who do you tell? Is there any chance of actually having an influence on an actual future project?
That’s a good question. I also wonder in what way passionate bloggers can influence actual decision making, beyond just … well, blogging.
Personally, I think the best strategy for “End the FRA” people is to try and woo the decent small government Republicans. (Mica, Amash, Paul, etc). There isn’t much hope in getting the notrain.com style Republicans on our side, and unfortunately the Dems have placed unions over transit riders as of late.
It goes both ways, really. The Indiana Republicans placed an anti-union poison pill; the Democrats refused to take it. I’m not sure I want people in charge who will sacrifice letting a city government improve its transit system with its own money on the altar of anti-union demagoguing. They’re every bit as complicit as the union-powered Democrats.
For what it’s worth, Amtrak’s NEC HSR proposal went through Woonsocket, so if you were affiliated with a politically-influential contractor you’d have a nicely perverse argument for Providence-Woonsocket regional rail. 😉
The rough maps in the proposal report show it following the Franklin Line for a while before diverging onto a greenfield ROW to reach the NEC. We’re lucky it’s unfunded, I suppose.
I wanted to add something about it in the post, but there was no good space to put it. So let me say it here: it’s fine to skip Rhode Island, if serving Hartford is more important (which it isn’t). But serving Rhode Island and its stop in Woonsocket is the rough equivalent of having HSR circle New York on I-287 and serve the region with stations in White Plains and Morristown.
You do know that Amtrak changed the stop to Providence in its plan.
I have heard, but never saw any confirmation.
I had fun talking about the New London – Westerly stretch on my Gateway Streets blog as a diversion from the usual St. Louis topics I write about. I figured that, between New London and Westerly, aligning a 180mph HSL along I-95 would save 17 minutes over the existing coastal alignment; doing the same between New Haven and New London would save an additional 25 minutes.
You mean this post? Yes, it would save a fair amount of time. Of course 17 minutes and even 25 minutes looks relatively small, but good rolling stock and better track maintenance in Metro-North territory would allow NY-Boston in much less than 3.5 hours at zero infrastructure – it would be about 2:30, which includes saving a few of those 42 minutes between New Haven and Kingston but also higher speeds in Massachusetts and in southwestern Connecticut.
For the record, the “correct” technical trip time for nonstop New Haven-Providence trains is about 35 minutes. This assumes higher top speeds (360 km/h) and more ambitious rolling stock than the Velaro (the N700-I, with 2 degrees of tilt cribbed from the E5/E6); slightly less ambitious assumptions, including scaling back top speed, would raise this to about 40 minutes. Current trip time is about 1:20.
This is exactly what I was thinking for upgrades. Utilize the I-95 which can handle I believe 270 km/h if you push a few eminent domains and curvature. Reducing the travel time to near 3 hours will definitely make taking the train more attractive. The next big hurdle would be New York-New Haven whether to follow Amtrak Vision or Long Island Tunnel. I could see some massive benefits via Long Island due to connectivity to the airports via AirTrain but would that provide enough incentive to transfer to train versus waiting for a connecting flight?
The problem with the Long Island tunnel is, first, it’s a tunnel. The cost schedule they use seems too easy on tunnels to me, but the only bases of comparison I have are two urban projects, and one (the Central Link in Hong Kong) I can’t find the numbers for.
But even if we put aside the enormous cost of an undersea tunnel, Long Island is not a good place for HSR. There’s too much suburban development. Existing ROWs are more valuable for commuter rail than for high-speed rail; the Penn plan is to follow the Hempstead Line and the Central Railroad of Long Island, which have tons of grade crossings and are surrounded by residential NIMBYs. That alignment has every problem that the New Haven Line has, only worse. Better would be to follow existing alignments with some cutoffs of the worst curves, and reelectrify the LIRR Main Line with catenary so that trains that would ordinarily go just NY-DC could run through to Jamaica, Mineola, Hicksville, and Ronkonkoma. I tried running their unit cost numbers on my main line alignment – no promises about having done so correctly – and it’s as I thought $5.5 billion from New York to Boston for infrastructure, though it excludes 25% managerial overhead.
Jamaica, Mineola, Hicksvile, Ronkonkoma has more people than New Rochelle, Stamford, Bridgeport, New Haven. The Main Line is moderately straight. The curves are near the places where you would be stopping on anything but the super express. Let the Regional toddle along the Shore Line or SLE toddle along from New London to Grand Central. Let HSR trains switch from the Connecticut Turnpike to the platforms under New Haven Union Station and then tunnel to Long Island. Yaphank looks good, nice wide row down the middle of the Moses extravaganza of Willam Floyd Parkway/CR46. The environmental clearances would be a PITA but it doesn’t have to be in a tunnel either. Long Island Sound is moderately shallow, something like the Chesapeake Bay Bridge Tunnel might be cheaper. Or along the top of the dike that keeps Long Island sound ten feet lower than the ocean….
You get all sorts of oooglly goodness out of it too, just like Altamont. Grade separating and quad tracking the Main Line for one…
I agree with Alon about tunnels. To center a project about a long undersea tunnel is a risk-maximizing strategy. But if you’re going to do it, then it makes sense to stay on Long Island as long as possible. The LIRR Main Line east of Ronkonkoma is single tracked and dark. To use it for HSR doesn’t disrupt anything. It’s fairly straight and the land around the few curves is rural enough that easing the curves would be cheap. So stay on it as far into the North Fork as practicable and then tunnel across the Sound so that the Connecticut portal is east of the Connecticut River. At that point (somewhere around Old Lyme) hook into Alon’s I-95 alignment. I-95 has a fairly wide median from there to the RI State Line.
Still, this is high risk.
We can cut off the curves on the New Haven Line too, and run high speed trains to Providence and New London also, at 300 km/h.
I’m not familiar with Hartford or Providence, but I agree with you since it doesn’t make sense to bypass such a big part of the line that is already suited for real 300km/h HSR.
I also notice that your HSR map:
(1) Takes an unusual route through Baltimore
(2) Keeps the current alignment through Zoo Interlocking
(3) Does not include a bypass of Frankford Junction
(4) Leaves the Elizabeth S-curve in place.
I imagine there are reasons for all of the above, and I’d love to see your evaluations.
Yes, there are explanations, but they aren’t going to be satisfactory. The Baltimore route is the Great Circle Tunnel; I was working off of descriptions of the proposal that didn’t have a map. The Elizabeth S should be fixed, yes – this is what I meant by “rough draft” (in particular, I missed a lot of short, sharp curves but thought the curves in Maryland were a bigger deal than they are). Zoo is unfixable at reasonable cost. Frankford is fixable – an elevated straightening could ease it to good-enough.
Greater Greater Washington post #3369 has a picture of Baltimore tunnel replacement alternatives and a link to the 2005 FRA study.
The benefits argument for Hartford is that it needs to be on the mainline, where Providence doesn’t.
Hartford’s problem, potentially Hartford’s asset, is that it’s doubly liminal. We tend to think of the BosWash conurbation as one big splotch on the map. But it’s really two distinct economic entities: Greater Boston to the east and the New York-Washington (politics and money) axis to the west and south. Hartford currently lies in neither. It has only tenuous economic links to both. But with better communications, if it were midway between them on the HSR mainline, it could potentially profit from stronger links to both. Providence, on the other hand, is firmly within Greater Boston. An HSR link to New York is less valuable.
I also think you’re too quickly dismissing the benefit to Worcester. Currently Worcester has essentially no intercity passenger service. The Boston branch of the Lake Shore Limited doesn’t count. Access to the Boston-New York mainline, even via a parkway station, is a massive improvement. Worcester isn’t that negligible a city. Providence is bigger, but only by about 30%. And Providence already is served by the Shore Line, which isn’t going away and, as you note above, could be considerably faster even with no infrastructure changes.
Also, you’re assuming that the HSR mainline should run through New Haven. The PennDesign alignment made the same assumption. But it’s a shaky assumption. The Amtrak Vision didn’t make it. Its alignment crossed to the I-84 corridor in New York, intentionally to bypass the Metro-North infested New Rochelle to New Haven segment. One can criticize the Vision alignment: Hell Gate – “then a miracle happens” – I-684 – I-84. But there’s strong motivation behind it. Even if there’s an argument that Providence should be served before Hartford, it’s not strong enough to insist that the alignment pass through New Haven.
Finally, all this assumes that there is a cost benefit argument for building HSR between New York and Boston. As far as I know, no-one’s made that argument. The argument that both Amtrak and PennDesign made was that the benefit/cost ratio for Boston-Washington was greater than 1. But that’s using the benefits from New York-Washington to justify the costs of New York-Boston. I haven’t seen an argument that the marginal benefit of extending Washington-New York HSR to Boston exceeds the marginal cost. I’m not saying that it doesn’t. Just that no-one’s shown the calculation.
The alignment through Springfield could benefit ‘secondary’ rail lines, most notably Boston-Albany, and connecting Vermont/Montreal with Boston and New York. Although these may not affect the cost/benefits in the decision between either the Northern or Southern alignment between Boston and New York.
In general it would be nice if there could be some actual 200Km/h+ regional lines connecting the regions in the North-East, because of the network synergies; the potential to offer much more population at reasonable speed. I’d say that speed is less of an issue than capacity – for example, would you rather triple the speed on the North East corridor, or triple its passenger-capacity?
Very very easy and relatively cheap to double the capacity of the NEC. Just buy more cars and run longer trains. Quadruple the capacity by buying more cars and running twice as many trains. Only problem then is capacity between Sunnyside Queens and Kearny NJ. Otherwise there’s plenty of capacity to double Amtrak’s frequency….kinda moot unless you increase speed because there won’t be the demand.
Well, that’s because everybody assumes HSR is competing with airplanes, rather than buses.
How big is the bus market along the NEC, compared to the air-market? Quadrupling capacity (which you alude could be done today, basically) would allow much more affordable fares, fares that could be competitive with bus travel; on the NEC trains are already (much?) faster than buses, and they are much more convenient.
As for the capacity constraint of the tunnels surrounding Manhattan, I wonder whether it would be possible to link two trains together in Jersey/Queens, and run them together as extra-long trains through the tunnel. That could be done by LIRR/NJTransit as well.
(In Hamburg, Germany, the airport train actually splits off from a normal suburban train.)
The bus market is pretty big, at least for trips under 250 miles. The low-cost carriers like MegaBus, BoltBus and the Fung Wah charge about $20 for a non-discounted one-way ticket. They generally pickup at curbside instead of a bus terminal, except in Boston they use South Station. Average trip time is similar to driving, choice of route is up to the driver, and they do get stuck in traffic sometimes. They seem to be doing quite well. They do not have to pay their fair share for highway maintenance or terminal space, which means they are highly subsidized by the government, similar to all other trucks and buses.
I don’t see how quadrupling capacity would lower fares. Supposedly, Acela recoups its operating costs. But the regionals do not, and they only fill about half the available seats. Quadrupling that capacity without increasing demand will just raise costs to operate.
How big is the bus market along the NEC,
Enormous if you count the commuter buses. A fraction of the intercity train travel.
Keep the math simple. Amtrak has two trains an hour most of the day. South/West of New York there’s the Keystones absorbing traffic between Philadelphia and New York. For a few hours of the day they run a second Regional between NY and DC. A bus has 50-60 seats. Acela has 304. The Regionals, it depends on how many cars the train has.
…. so one Acela = 6 buses.
extra-long trains through the tunnel
NJTransit and the LIRR already run 12 car trains. Extra long trains take an extra long time to clear the interlockings.
My guess is that Amtrak is about even with Megabus and Bolt combined, or a bit ahead. On the big markets – NY-DC, NY-Philly, NY-Boston – the timetables of Megabus and Bolt are such that if about 70-80% of the seats are filled, then they’re even with Amtrak on those city pairs. Amtrak has a big advantage on smaller markets – e.g. NY-Providence is 400,000 per year on Amtrak, but Bolt doesn’t even serve it, and Megabus has 5 roundtrips per day, which corresponds to 100,000-150,000 annual passengers.
The I-84 alternative has very steep grades in that are going to make that cost-prohibitive. If build alongside the interstate carriageway there’s at least 1 spot, if not 2, between Vernon and Willington requiring tunneling because the railbed simply won’t be able to keep up with the steepness of the highway. Exits 68 to 69 is absolute no-go for surface trains because of steepness of the hill. Detouring around Tolland a few miles runs smack into the same 600+ ft. sudden elevation that cuts across that whole swath of the state, so there are no easy alternatives.
Better alternative would be the I-384 corridor. Route 6 from Bolton to Willimantic is such a horrifying and unsafe drive that they are going to have to build the expressway extension hell or high water. After 50 years of trying they almost had a routing 10 years ago that the locals would agree to, which included several hundred foot wide forested greenway median, but the Army Corps of Engineers spiked it for the Plan B routing with more land-taking that’s a total nonstarter with the towns. Since the road situation is getting untenable, what they should do is remount the effort again in another decade…but pitch it as highway with rail. Advantages:
— The elevation is reasonable.
— The landbanked portion of the NYNE ROW crosses the highway at Bolton Notch at the end of current I-384 and Willimantic at the end of the current discontiguous expressway segment built for this road in the early 70’s. That’s existing access onto the new-construction ROW.
— It would be suited to max speeds out the gate, whereas restoring the NYNE RR from Bolton to Willimantic has its own curvature issues.
— The EIS would be shared with the expressway, cutting down the cost by sharing it with highway funds.
— It doesn’t touch the rail trail on the NYNE, which removes a significant opposition bloc. The Vernon-Willimantic section on the old ROW passes through a state park where the trail can easily be relocated.
— It might help sway the last blockers to doing the expressway by presenting somewhat more environmentally efficient multimodal advantages (i.e. trucks and cars off the road and on the rails so the highway doesn’t later have to be expanded to 6 lanes).
— Freight advantages: It would allow NECR (and possibly P&W) a double stack freight route to Hartford from their high-capacity north-south lines. They already interchange high-clearance cars amongst themselves east-west between Willimantic and Plainfield. Connecticut Southern, the shortline freight RR that operates the active part of the line from Hartford to Manchester, is also owned by NECR’s corporate parent RailAmerica and P&W already interchanges in Hartford from the south. Good synergy with the carriers there.
— Commuter rail: Hartford-Willimantic is well-needed in the medium term. That would also permit continuing in-state service from Hartford to the casinos and New London on the NECR mainline, which is already rated for 60 MPH and doesn’t need need much bump to get speeds competitive with Routes 2 and (proposed) 11. NECR is already making noise about wanting to run passenger trains on limited basis in Eastern CT to compete on the cheap with the ubiquitous casino buses and reel in some track improvements.
— Max utilization: all of the above would push this higher-priority to lock in the future HSR route to the east, and it’s a lot more doable by pooling the highway, high-capacity freight, and commuter rail resources. So long as the ROW is future-proofed for HSR–no grade crossings, room to add a third track to keep the freights well-separated from the high-speed trains, and pre-dug wiring conduits they can string cable through when it’s time to electrify–then this gets a lot more academic.
All you would need to do from there is:
1) Get the Springfield Line from New Haven to Hartford up to HSR standards or as close to it as possible.
2) Electrify to Willimantic.
3) Figure out the ROW for pushing east:
— Providence has the active Willimantic Branch taking it to Plainfield…then the ROW in Rhode Island needs restoration.
— The Willimantic Branch is a little curvy, so they could always continue I-384 east to I-395 and the state line, then carve out a dip through the woods a couple miles south to meet the landbanked NYNE in Moosup and continue on through RI.
— The NYNH&H Air Line is landbanked and available to the northwest, and does have the ROW geometry to support good speeds. Rather than taking it through Woonsocket and the Franklin Line, which misses population centers, it’s better to send it due north from Putnam to Worcester on P&W, then east on the Worcester. P&W is almost arrow-straight here and would support the speeds if there were enough passing sidings to get around freights. Worcester’s a major terminal in the making with the MBTA, east-west Amtrak intercity, and likely RIDOT Providence-Worcester commuter rail service meeting at a single node (plus a freight-active, if very curvy, line that could be upgraded for direct connections to Lowell and New Hampshire. And the Worcester Line is a major trunkline that once was tri-tracked (although the Mass Pike cannibalized some of that space east of Route 128), will probably have its last 4 grade crossings whacked long before this, will likely be electrified for commuter rail by then if the MBTA is smart.
If I had to pick, the 384 + Air Line + Worcester build serves the most interests and involves the most consolidated infrastructure. No, that’s not perfect for total freight and passenger separation, but those are facts of life in the Northeast. This build at least offers a clean blueprint for separating out the freight traffic from the get-go on the Hartford-Willimantic, Putnam-Worcester, and Worcester-Framingham sections with tri-tracking.
As for Providence…a little costlier, but also doable. So why not divvy up traffic at Willimantic in choose-your-adventure style. Build the Worcester leg first because that’s easier and recycles more existing infrastructure with excess capacity. Then build the Providence fork with either the next leg of I-384 to I-395 or by doing what they can with straightening out the Willimantic Branch. Then restoring the ROW in Rhode Island. Worcester’s pretty hard to ignore with current 181,000 population (slightly higher than Providence) and better rail connections fanning out in more directions. But as suggested, Providence can’t be left behind.. This doesn’t have to be an either/or…just a first/second sequence if the Hartford-Willimantic route gets laid out ahead of time. Then you can truly downgrade the Shoreline to non-preferred local route. New London’s not going to suffer with ample commuter rail in every direction.
Western inland bypass?…good luck with that. The NIMBY problems are so bad, land-taking so expensive, and construction costs so high I’m not sure it’s realistic at all by 2040. They’d be better off getting the best NEC they can conceivably get Washington-New Haven on the current ROW, then using the Springfield Line and doing this far easier and hopefully multi-pronged eastern leg.
Brainfart…I meant “northeast” on the Air Line.
The Connecticut state rail map shows the ROW’s in question: http://www.ct.gov/dot/lib/dot/documents/dpt/rails2x3.pdf. The current I-384 terminus crosses the landbanked NYNE in Bolton exactly at the spot it takes the easterly turn from its due-south jog through Bolton Notch. Very straight east of Hartford except for the topography-pinned Bolton Notch dip. The proposed highway routing the Army Corps was being obstinate about runs slightly north of the Bolton-Willimantic segment currently hosting the trail. Note how curvy the existing ROW is, so that’s illustrative of how much a highway median replacement is going to speed things up. It then leaves the highway on the little freight-active tip in Columbia.
And then you can see the choose-you-adventure possibilities. Air Line has curves, but it doesn’t deviate much from a Point A-to-Point B line and most of them are not problematically tight. And then P&W is really, really straight from Putnam to Worcester.
Willimantic Branch has some curvature issues to Plainfield, but generally speaking it’s nice and straight en route to Providence once it gets on the other side of I-395. The proposed second I-384 leg between Willimantic and I-395 would also straighten this out considerably if it incorporated rail, but that’s a project much further off than the vastly more urgent Bolton-Willimantic connection.
That Tolland stretch between Exit 65 where the landbanked ROW touches and Exit 70 in Willington where NECR crosses north-south is the place where the I-84 routing is going to get bogged down in either ludicrously expensive tunneling or implausibly steep grades.
The curves around Willimantic are just terrible. They’re too tight for any high-speed running, and the terrain is steep and does not favor easements. Going through Plainville involves a curve of radius about 500 meters in Lisbon; with passenger-only superelevation and top-notch tilting trains (which are limited to 250 km/h no matter how good the track is and are a pain to maintain), that’s 140 km/h. There are many similar, only slightly better curves elsewhere on the route. A more direct route to Putnam bypasses that curve but introduces others.
People continually overrate the curviness of the New Haven Line because of the low speed limit in Connecticut (imposed by track maintenance issues and CDOT’s dispatching needs) and the very low cant deficiency (again imposed by CDOT). The only really unfixable bit there is Bridgeport, though Darien is not too good either. Most of the line is straighter than the alternatives nearby, and straighter than the Air Line, which despite the name is curvy as hell, and not even that direct if you go through Hartford and Route 6 or through Plainville. To put things in perspective, away from its worst sections, it’s about as straight as the P&W line from Putnam to Worcester (and then the Worcester Line is curvy).
Some of those ROWs would be nice routes for regional trains or for low-speed intercity trains connecting Hartford, Norwich/New London, Providence, and Middletown. But they can’t accommodate anything high-speed. It’s fine – not all and not even most traffic needs to be fast – but a high-speed mainline needs curve radii measured in kilometers. In a regional situation, it’s okay to run on freight-primary track, since there is a lower mismatch in speed, probably less frequency since none of those lines will ever be as busy as the Northeast Corridor Line, no need for double-tracking, and a lower design speed permitting lower superelevation.
Finally, bundling anything with a highway is a cost increaser. The food chain in US transportation is such that road projects are frequently not considered road projects, while things that are not rail projects are frequently considered rail projects. Parking garages at train stations come out of transit budgets. The MBTA is being saddled by debt coming out of court-mandated Big Dig mitigations. In a road-rail situation, expect all planning costs to be budgeted to rail, especially if the rail part is billed as a high-speed mainline; moreover, expect all mitigation money to be billed to rail. You’ll be lucky if the highway budget contributed the marginal cost of grading the ROW for both the railroad and the expressway.