What's the realistic speed ceiling for the Shore Line in Connecticut? I get New Haven-NYC is always going to be bit cramped and the bends/bridges in CT aren't optimal for proper true-blue HSR, but surely there's got to be some wiggle room once the river crossings are upgraded.
Not much higher than it is now. From Rich Green's old Connecticut track map, here's what I've got for track speeds, New Rochelle to Attleboro station. From 2007, but nothing significant has changed. Individual speed restrictions
within a track speed zone are indented; those are the ones only a few hundred feet long around modest curves or local station approaches (i.e. small enough to not force a change in speed limit outside of 1 or 2 signal blocks). I omitted the ones that were only 5-10 MPH variances because in an Amtrak-length schedule those don't even dent the schedule padding margin for error and are 100% non-entities in any NEC improvements conversation.
Don't know what the individual changes in speed limits are inbound of Sharon station, but that's only 18 miles to Boston where the 128 station stop and SW Corridor/terminal district come into play. All I know is it's not slow until you approach Back Bay, and other than *maybe* a few MPH from 128 to Forest Hills when they add back Track 3 Canton-Readville and Track 4 Readville-Forest Hills there's no potential for making it any faster. Certainly nothing worth more than 1-2 minutes to the schedule.
New Haven Line
- Shell Interlocking + New Rochelle station -- 70 MPH from Grand Central side of junction, 45 MPH from Penn side of junction
- New Rochelle to Harrison -- 90 MPH
- Harrison to Port Chester -- 75 MPH
- Port Chester station to CT state line -- 45 MPH (individual curve)
- CT state line to Cos Cob bridge -- 70 MPH
- Cos Cob bridge to Stamford -- 75 MPH
- Stamford station terminal district -- 50 MPH
- Stamford terminal district to New Caanan Line split -- 60 MPH
- NC split to East Norwalk -- 70 MPH
- Walk Bridge -- 45 MPH (may be less today)
- East Norwalk to Bridgeport station approach -- 75 MPH
- Bridgeport curve to Peck Bridge -- 45 MPH (note: no speed restrictions on 1998-construction Peck Bridge)
- mid- Bridgeport curve -- 30 MPH
- Peck Bridge to Devon Bridge -- 75 MPH
- Devon Bridge + adjacent Waterbury Line split -- 60 MPH
- Waterbury split to New Haven -- 75 MPH
- Milford station approach -- 60 MPH (4 tracks temporarily drop to 3)
- New Haven terminal district to State St. station -- 30 MPH
Shoreline
- State St. to Springfield Line split -- 50 MPH
- Springfield split to Clifton St. tunnel -- 70 MPH
- Cedar Hill freight yard curve -- 60 MPH
- Clifton tunnel to Branford station -- 80 MPH
- Branford station to MP 86/Leete's Island -- 120 MPH
- MP 86 to MP 87 -- 95 MPH
- MP 87 to Guilford station -- 115 MPH
- Guilford station to Madison station -- 125 MPH
- Madison station to Westbrook station -- 115 MPH
- Westbrook station to Old Saybrook quad-track -- 90 MPH
- Old Saybrook quad-track + station to South Lyme/MP 110 -- 110 MPH
- Connecticut River Bridge -- 30 MPH
- MP 110 to Niantic River Bridge -- 90 MPH
- Niantic River Bridge to Shaw's Cove Bridge -- 75 MPH (no restrictions on 2012-construction Niantic or 1984-construction Shaw's Cove bridges)
- (Miner Ln. grade crossing)
- Shaw's Cove to New London Station -- 25 MPH
- (Bank St. Connector, State St., Winthrop Blvd. grade crossings)
- New London Station to Thames River Bridge -- 45 MPH (no restrictions on 2008-rebuilt Thames bridge)
- Thames River to Old Groton Industrial Track junction (3-track territory) -- 65 MPH
- Groton Ind. Track to Mystic station -- 90 MPH (no restrictions on 1984-construction Mystic River Bridge)
- MP 129 -- 70 MPH (single curve)
- (School St. grade crossing)
- Mystic bridge + Mystic station to Walkers Dock grade crossing -- 75 MPH
- Mystic station + grade crossing -- 60 MPH (sharp single curve)
- (Wamphassuc Point Rd. grade crossing)
- Walkers Dock to Bradford, RI -- 90 MPH
- Bradford to Shannock/MP 154 -- 105 MPH
- MP 152/Carolina -- 85 MPH (single curve)
- MP 154 to East Greenwich/MP 172 -- 150 MPH (pending 165 MPH)
- MP 160 -- 130 MPH (single curve)
- MP 170 -- 130 MPH (single curve)
- East Greenwich to Gannon Chemical freight siding/MP 174 -- 115 MPH
- MP 174 to Port of Providence Industrial Track -- 150 MPH (pending 165 MPH)
- PoP Ind. to MP 182 -- 100 MPH
- MP 182 to MA state line -- 70 MPH
- MP 182 -- 55 MPH (single curve)
- Atwells interlocking (junction with P&W FRIP track) -- 60 MPH
- Providence station approach -- 30 MPH
- MA state line to East Junction -- 125 MPH
- East Junction to Sharon curve -- 150 MPH (pending 165 MPH)
Now...New Haven Line
looks dog-slow with all those mid-70's. And the Shoreline in CT looks better than it really is with those 90's and low-100's. But that has very little to do with speed-killing curves. The New Haven Line is significantly less curvy than the Shoreline. The problem is simply congestion. You can tart of the two center express tracks all you want with superelevation and re-spacing for tilt so the geometry supports higher speeds...but just as many Metro North trains run express with wide stop spacing on the inner tracks as run local with dense stop spacing on the outer tracks. Enough so that there's only so many crossovers you can throw in there to weave around them before the passing maneuvers themselves set the speed ceiling.
The Shoreline just has Shore Line East and RIDOT-to-be. There will never be more than one middling-schedule commuter rail co-tenant anywhere from State St. to Wickford Jct. So not only do the commuter trains not impose the upper speed limit out of their sheer numbers and close spacing on all tracks, but blasting by at full speed on a crossover is much easier when both the commuter trains and their station stops are so much more widely spaced. Metro North would be considerably faster than the Shoreline if it were blessed with SLE's schedule. Strictly in terms of track geometry, the Shoreline is a way uglier piece of engineering. And the fact that it doesn't serve any particularly large cities (Old Saybrook and New London are not exactly must-haves for true HSR as long as the Regionals presence stays robust) makes it the hands-down better bypass candidate.
So in MNRR territory you're always single-file behind some commuter train with not nearly as many opportunities to cross over and pass as you would...say, in the 3+ tracks of SEPTA and MARC territory. Or even NJ Transit for that matter, since not even the crush-load Trenton Line with its double-digit car trains can hold a candle to the sheer density of New Haven Line service levels. That's a 90 MPH uppermost limit, but since the MNRR trains that travel the express tracks are turning in and out the whole way to make their wider-spaced stops the EMU's generally don't have enough acceleration room to hit their full 90 MPH rating for more than small stretches...much less hit the theoretical max of the straighter track geometry in ideal (i.e. if there were no trains ahead) conditions. This will never change. You can nip and tuck on just a couple tough curves and just a couple tilt zones to save a couple minutes, but it's the continent's densest-service commuter rail line all the same. And you have to engage it if you want to hit the population centers.
You don't have room for 5 or 6 tracks anywhere except for a small stretch north of the Shell interlocking between New Rochelle and Larchmont. So 4 tracks now, 4 tracks forever. 5-6 tracks at Shell combined with a grade separation of the junction would help a ton to sort the merging traffic from Grand Central and Penn, but doesn't help for passing upstream. It mainly serves to whack that painful 45 MPH restriction coming off the Hell Gate Line so those trains can keep doing 100 MPH from Pelham Bay all the way into New Rochelle station.
The only other significant curve that can be eliminated is the one between Stamford and Noroton Heights where if the I-95 cavity were widened out to the abutter property lines with retaining walls you might be able to fit it alongside (or do 2 bypass tracks along 95 and 4 local tracks on the old alignment) and simply have the New Caanan line absorb the 4000 ft. due-northward dive of the old alignment) to a new junction. Most of the other mini-bypasses that look like they could be done just from scrolling on Google Maps need to take into account: how much speed are you going to gain from the straightening when commuter traffic is still the same?
I think in the end you learn to love the New Haven Line for what it is, and focus on running up the score with more 165 MPH territory in the Jersey swamp, Delaware, the Eastern CT-Providence bypass, mini-bypasses of a mile here/there, altering curves a couple degrees where room allows, and superelevating curves for tilt where that matters. Squeeze every second you can north of New Haven and south of New Rochelle so the savings are banked in for coasting through Fairfield County. It's not like the LIRR Main Line + a cross-Sound tunnel is any less a congestion pickle. It's arguably more daunting because it starts with fewer tracks and has many more branchline mouths to feed. And as for the Westchester bypass that misses too many population centers...it's as engineering-improbable with the terrain along I-84 as it is impossible to get the dense abutters to support.