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Old 09-18-2018, 09:53 PM   #3381
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Re: Crazy Transit Pitches

^ So you're saying there'd be plenty of space for the retail concourse then?
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Old 10-14-2018, 09:58 PM   #3382
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Re: Crazy Transit Pitches

I don't know if this necessarily counts as a "transit" pitch, but...

What about a pedestrian/bike only bridge that connects East Boston, Charlestown, and the North End. It's pretty impossible to bike from East Boston to the rest of the city. It would connect well to the bike lane on Commercial Street in the North End. There are small piers that could be used as landing sites for each of the three sections of the bridge. It would also add much better connectivity from East Boston to Charlestown than the new Silver Line probably ever could. If Boston wants to get serious as a biking city then this could be the crown jewel of its bicycle investments.

So let me know why this is impossible/unfeasible etc!
Also how high would this have to go? I know there are still drawbridges along the chelsea river...

Here's a google map of what essentially what I'm talking about:
https://www.google.com/maps/d/u/0/ed...481156123&z=14
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Old 10-15-2018, 11:09 AM   #3383
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Re: Crazy Transit Pitches

Interesting idea. My eyeball measurement says that's 3000 feet from East Boston to the North End. Certainly fine for cycling, might be a bit too long out on the harbor for some pedestrians. As for height, it would need to be high enough for the tanker ships bound for Chelsea. A quick google says 13 meters, which is very doable as an incline for the bridge. I'd say the biggest reason this goes under crazy transit pitches is that it would be crazy expensive to build. Even with a huge usage rate compared to cycling elsewhere in the city (unlikely), it would be very expensive per expected trip over the likely bond service period.
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Old 10-15-2018, 11:14 AM   #3384
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Re: Crazy Transit Pitches

Cut and cover the Grand Junction for a rail tunnel with Bus lanes (BRT) or light rail on the surface above. Mostly cut and cover except for a dip under the red line.

https://www.google.com/maps/d/viewer...y7&usp=sharing

Design it sooner rather than later so the I90 realignment design can take into account either a portal on that side of the river or the viaduct.
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Old 10-15-2018, 11:19 AM   #3385
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Re: Crazy Transit Pitches

Quote:
Originally Posted by tangent View Post
Cut and cover the Grand Junction for a rail tunnel with Bus lanes (BRT) or light rail on the surface above. Mostly cut and cover except for a dip under the red line.

https://www.google.com/maps/d/viewer...y7&usp=sharing

Design it sooner rather than later so the I90 realignment design can take into account either a portal on that side of the river or the viaduct.
Not sure why this would even be necessary. Sure Kendall is a powerhouse but this would really only serve Worcester Line riders and that isn't much of a draw when a lot of these workers are choosing to live close to work (and can afford to). Spend the money on the NSRL.
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Old 10-15-2018, 11:20 AM   #3386
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Re: Crazy Transit Pitches

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Originally Posted by DAVE View Post

So let me know why this is impossible/unfeasible etc!
Also how high would this have to go? I know there are still drawbridges along the chelsea river...
So you want to impede ship traffic even more?
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Old 10-15-2018, 11:26 AM   #3387
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Re: Crazy Transit Pitches

Quote:
Originally Posted by DAVE View Post
I don't know if this necessarily counts as a "transit" pitch, but...

What about a pedestrian/bike only bridge that connects East Boston, Charlestown, and the North End. It's pretty impossible to bike from East Boston to the rest of the city. It would connect well to the bike lane on Commercial Street in the North End. There are small piers that could be used as landing sites for each of the three sections of the bridge. It would also add much better connectivity from East Boston to Charlestown than the new Silver Line probably ever could. If Boston wants to get serious as a biking city then this could be the crown jewel of its bicycle investments.

So let me know why this is impossible/unfeasible etc!
Also how high would this have to go? I know there are still drawbridges along the chelsea river...

Here's a google map of what essentially what I'm talking about:
https://www.google.com/maps/d/u/0/ed...481156123&z=14

How about make it a floating bridge at sea level? Just move the sections out of the way horizontally instead of vertically like a draw bridge.

Something like this: https://www.travelandleisure.com/cul...vernors-island

I mean probably too much boat traffic to make it practical or desirable. But would be kinda fun.

Practically speaking how about just a couple more water taxis stops on the East Boston side of the harbor. Looks like there are 7 water taxi stops on the Downtown side of the harbor, 4 in Charlestown, but only one in East Boston.
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Old 10-15-2018, 11:38 AM   #3388
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Re: Crazy Transit Pitches

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Originally Posted by vanshnookenraggen View Post
Not sure why this would even be necessary. Sure Kendall is a powerhouse but this would really only serve Worcester Line riders and that isn't much of a draw when a lot of these workers are choosing to live close to work (and can afford to). Spend the money on the NSRL.
Figured it would be a lot lot cheaper than NSRL. Being mostly cut and cover and the real benefit would be connecting Kendall with the new Harvard owned land at Beacon Yards that is being freed up by moving the Pike.

I see Beacon Yards as an extension of or a new Kendall Square level of development if it gets properly built out. Better connecting the Harvard R&D ecosystem with the MIT R&D ecosystem to continue to make Boston/Cambridge the undisputed top Technology and R&D center.

And it really would benefit both Kendall/Cambridge/MIT and Boston/Harvard to make that direct connection with transit versus today's bus routes that go across gridlocked city streets.

The commuter rail part is almost incidental to my thinking. Just getting it out of the way mostly to make way for either light rail (green line trolley) or BRT on the surface.

Especially if NSRL is stalled then this seems the best way to actually make good use of that underused line and right of way.
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Old 10-15-2018, 05:24 PM   #3389
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Re: Crazy Transit Pitches

Quote:
Originally Posted by DAVE View Post
I don't know if this necessarily counts as a "transit" pitch, but...

What about a pedestrian/bike only bridge that connects East Boston, Charlestown, and the North End. It's pretty impossible to bike from East Boston to the rest of the city. It would connect well to the bike lane on Commercial Street in the North End. There are small piers that could be used as landing sites for each of the three sections of the bridge. It would also add much better connectivity from East Boston to Charlestown than the new Silver Line probably ever could. If Boston wants to get serious as a biking city then this could be the crown jewel of its bicycle investments.

So let me know why this is impossible/unfeasible etc!
Also how high would this have to go? I know there are still drawbridges along the chelsea river...

Here's a google map of what essentially what I'm talking about:
https://www.google.com/maps/d/u/0/ed...481156123&z=14
Well...the Harborwalk is gradually getting filled in through Charlestown. Basically, you need a cycle track alongside Medford St. to bypass the Massport freight terminals and connect the small Alford St./Schrafft's Center rump with the start of the Little Mystic-to-Navy Yard path. The new Washington St. bridge then has the pedestrian facilities to make a proper connection to the North End Harborwalk. Then there are the various proposals to fill in the gap alongside MBTA Charlestown Garage to link the Alford trail head with the whole of the Mystic path system in Somerville/Medford.

Harbor-crossing on foot/bike to Eastie just isn't going to happen. Too much freight terminal area along the navigable Chelsea River to try to stitch something together through Chelsea, and the Tobin + tunnels are the literal only intracity/near-intracity connections at all. Waterways are much too busy and tides too big a factor to try to do a floating-anything.


What Eastie does have going for it is pretty excellent path connectivity of its own with the Greenway and the surface path along the Blue Line from Logan Station to Constitution Beach.
  • Few blocks of gap filler along Marginal St. connects the grade-separated Greenway with the little rump of Harborwalk around the Logan ferry terminal.
  • Ample opportunity to strengthen the connections to Revere by extending the Greenway Connector off Constitution Beach along Blue Line/Bennington St. to Suffolk Downs and Revere Beach Blvd. @ Eliot Circle. In fact, any bigtime redev for Suffolk Downs pretty much demands that this particular path extension get heavily prioritized as a build prerequisite for that site.
  • Winthrop spur -- Plunking down a side path from the Constitution Beach trail head alongside Orient Heights Station's parking lots puts you on-alignment with the former BRB&L Winthrop Branch ROW. Put a small footbridge on the old RR marsh crossing's abutments and you're connected to Morton St. in Winthrop well away from the heavy traffic on MA 145. Install a cycle track along the marsh for grade separated connection to Fort Banks. A small existing path on the railbed already connects Ft. Banks Park with the 3-way intersection of Revere St. / Crest St. / Highland Ave.
    • 3 blocks west up Revere gets you to Short Beach, which has a very nice path wrapping around to Beachmont (and a few short blocks of gap-filler at the north tip from wrapping around and completely re-joining the Greenway Connector extension @ Eliot Circle.
    • 3 blocks east down Crest gets you to Winthrop Shore Drive en route to downtown. Tart up Shore Dr. with a little bike stripage and add some safer route upgrades around downtown to strengthen the connectivity.
    • 4 blocks north up Highland gets you to Ft. Heath Park.
  • NIMBY-be-willing...construct a cycle track along the beach on Rice Ave. that connects the Revere Beach Blvd. path's Carey Circle trail head to the Lynnway drawbridge. Right now there's some incomplete path segments there and a comically short seawall (so much stubbier than the one along Revere Beach Blvd. that it's near-zero practical protection for the beach-facing homes on Rice). A project to top off the seawall a couple more feet and complete a cycle track alongside it gives Revere complete grade separated path coverage.
  • Take the Bike to the Sea trail head in Lynn @ Bennett St., tart up a couple blocks of ugly auto chop shops on Bennett out to Commercial St. with a little streetscaping, and duck under the RR bridge on Commercial...and you've got realistic shot of connecting the Lynn and Revere paths over the Lynnway drawbridge. Once on the other side of the Eastern Route tracks, do a grade separated path behind the Lynnway biz strip out to those new apartments being erected by Riverworks. Angle over to Lynnway from those apartments right before the bridge, cross the bridge on as tarted-up a sidewalk as the existing structure allows (probably requires a lane-drop since current sidewalks are uselessly narrow). Then install a ped underpass on the Point of Pines side of the bridge for grade-separated link-up to Rice Ave.
^^A complete circuit from Logan ferry terminal to Everett + Mystic path system (with spur/loop route to Winthrop)...broken only by a make-the-best-of-it single bridge and couple blocks of low-traffic Lynn side streets.


So long as you aren't getting too overly hung up by the Boston City Line being its own manifest destiny, it's better to group Eastie as part of the North Shore's circuit of grade-separated paths and Charlestown as part of the downtown Harborwalk + greater Mystic system. They both scale magnificently well across their respective regions even if they don't remotely touch anywhere east of the Fellsway/MA 28 bridge over the Mystic. And the utilization is probably going to scale better North Shore-Eastie vs. Eastie-CBD anyway because Revere, Lynn, etc. are huge population centers much more starved for car-free commute variety than City of Boston -proper is.

You'll get plenty of bikes taken for a ride between Aquarium and Logan stations to get between networks if each side of the Harbor's path network grows out to its fullest. Maybe enough to upgrade the Aquarium elevators/escalators for easier bike transport or do up a couple Blue Line cars in the partially seatless "Big Red" setup to facilitate easier bike transport. Something like that would come MUCH sooner in the queue over wacky ped Harbor crossing schemes. Work the North Shore path network buildout as robustly as they are on the other side of the Harbor, then augment the natural transit connections like Blue and SL3/etc. for better bike friendliness. That's pretty limitless growth unto itself, with not an inordinate number of path gaps left to fill. Other than perhaps the Rice Ave. NIMBY's (who aren't necessarily make-or-break) none of those missing links are any biggie to plug together.
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Old 10-15-2018, 08:51 PM   #3390
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Re: Crazy Transit Pitches

Quote:
Originally Posted by tangent View Post
Figured it would be a lot lot cheaper than NSRL. Being mostly cut and cover and the real benefit would be connecting Kendall with the new Harvard owned land at Beacon Yards that is being freed up by moving the Pike.
Hardly. The Grand Junction from BU Bridge to Main St. is all on 1905 soft fill. Prior to that the railroad ran out on a causeway in the middle of the ancestral tidal river. Any tunnel construction there would require massive amounts of waterproof shielding to account for the water table in the former tidal bay in a sea level rise era where water levels in Charles Basin are going to be running consistently higher more of the time (exerting more influence on that fill water table) with acute vulnerability to overtopping. You might be able to "cut it and cover it" in a physical sense, but the waterproofing demands price it heinously more expensive per tunnel foot than standard-cost C&C.

At Main St. you'd have to be 100 ft. below ground...descending at <2% RR grades...to undercut the Red Line. On a sharp speed-killing curve negotiating the building pilings for the 8-story Cognitive Sciences building. With active pump rooms to prevent the high-and-dry and all- bedrock-anchored Red Line from succumbing to the storm drain effect of a catastrophic water breach from the lower level. Then start inclining up from that max depth under the 1969 filled-in remains of Broad Canal at Binney St. and do a little bit more waterproofing until back dry and level around Cambridge St.

It's entirely possible that tunneling under the GJ ends up nearly as expensive as the NSRL mainline tunnel (i.e. non-stations portion) because of sheer length of tunnel needing above-and-beyond waterproofing through Cambridge tidal flats vs. downtown between the I-93 slurry walls. Not even the portion of the NSRL mainline tunnel that swings slightly out under Ft. Point Channel between SS Under and the insertion point to 93 @ Northern Ave. ends up passing through much different soil properties. The poorest-drainage soil NSRL passes through is on the shallowest-dig first portions of the portal tunnels to their convergence point under the Pike Extension tunnel. And guarding against that vulnerability is much more about having multiple fail-safe flood doors near the portals themselves than soil properties on the descent. Portal locations @ Southampton and the Pike canyon are the areas of max inundation on a 50-year Boston flood map, so protection against the storm drain effect from the surface is a much bigger problem than preventing leaky walls deep below.

Through Cambridge you have to have nearly 1-3/4 mile of tunnel done with maximal leak protection on the pour AND active pumping for the storm drain effect converging on Main St./Red Line at point of maximum depth. Tack on an upper-bound per-foot construction premium for it all. The GJ "Under" tunnel is even worse by engineering dollar than waterproofing a mythical Mass Ave. subway from the Red Line @ Main St. (bedrock/former shore) to the Symphony area (former shore). The Grand Junction alignment would be even more cosmically expensive than that: over-dimension RR bore instead of Red Line-size, nearly a half-mile longer, descending much deeper, and staying more contiguously under landfill slop instead of anchoring shore-to-shore.


Quote:
I see Beacon Yards as an extension of or a new Kendall Square level of development if it gets properly built out. Better connecting the Harvard R&D ecosystem with the MIT R&D ecosystem to continue to make Boston/Cambridge the undisputed top Technology and R&D center.

And it really would benefit both Kendall/Cambridge/MIT and Boston/Harvard to make that direct connection with transit versus today's bus routes that go across gridlocked city streets.
I agree. That's why you just git-r'-dun and build the as-proposed Urban Ring BRT or LRT on that alignment sooner rather than later. NSRL is not a build prerequisite at all for ripping the GJ off the RR network and implementing a mode that can climb grades tall enough to grade-separate Mass Ave. and direct-share traffic signal cycles at Main/Broadway. Search back through many posts detailing why, but bolstered southside CR equipment independence is the only thing you have to do so north-south equipment swaps can persist couple times a week on the Worcester County detour instead of twice daily on the GJ.

Quote:
The commuter rail part is almost incidental to my thinking. Just getting it out of the way mostly to make way for either light rail (green line trolley) or BRT on the surface.

Especially if NSRL is stalled then this seems the best way to actually make good use of that underused line and right of way.
This isn't borne out by study evidence. They quantified MetroWest demand to Kendall and North Station in the Worcester-NS study, and it only found demand spikes big enough to merit 5 unidirectional peak-only schedule slots each direction. And that's because those direct slots corresponded with the times of day Red and Orange were choking the hardest under load on the BBY-NS and SS-Kendall transfers. All off-peak times the ridership for the direct Purple trains evaporated because Orange and Red made NS and Kendall via transfer within 2-4 minutes of identical (because the GJ is so slow), and a stiffening of regular Worcester-SS all-day frequencies through Yawkey-BBY-SS delivered more riders via those transfers than would be delivered by forking the line @ West Station and adding more NS directs up to the GJ's very limited capacity limits.

In short, the study conclusion was: there's no natural constituency for one-seat from MetroWest to Kendall at more limited frequencies than MetroWest to 1 unified CBD destination (SS). But there IS a giant festering problem with Orange and Red collapsing under overload that will force CR riders to anticipate alternatives during the most overloaded hours. Make Orange and Red perform better under load, and all demand--rush-hour included--is essentially all-satiated by having the certainty of reliable/predictable subway service fed by ever-increasing Worcester frequencies. A fairly emphatic conclusive pair of "FIX THE SUBWAY!" and "IT'S THE FREQUENCIES, STUPID!" answers if ever there were, since that MetroWest audience much more highly favors greater source frequencies into already-frequent transfers than occasional alt.-routed one-seats sharply limited by the Grand Junction's native capacity.

Obviously, the Urban Ring could serve the same need just swimmingly by adding a third transfer option to the mix @ West and lessen even further the need to provision for any Worcester-NS directs vs. just straight-on increasing regular SS frequencies. That's not a point in favor of threading two modes on top of each other on the Grand Junction ROW in some kajillion-dollar waterproofing dig. If anything it takes whatever remaining air is out of the RR tunnel idea and just ends up favoring a giddayup on the solo surface Urban Ring BRT/LRT build timetable.


I don't get this notion that's inflicted some threads here about "Well, they turfed the NSRL so I guess the next best thing is doing an East-West Rail Link because reasons." No...NSRL is about trans-CBD access. Consolation-prize "EWRL" is just a slightly modified path to the same CBD. Not thru the CBD to some truly MetroWest-inaccessible place like the North Shore or vice versa. We already know that the audience strongly favors robust Worcester frequencies meeting well-functioning transfer frequencies when it comes to all things CBD-reaching...and eschews the one-seat frequency-diluter when both pairs of the CBD transfer are on-time, meet frequently, and meet at their *most* frequent with no service forking. The goal isn't to spend billions dollars on a somewhat less dog-slow (but still pretty geometrically slow) and less frequency-diluted Grand Junction Under to artificially goose the one-seat frequencies enough to flip that equation on its head for the pride of Proving Self F***ing Right™ on an assumption.

Just follow the demand where it clearly is, and let the money follow. That means building the UR to establish that important West-Kendall-NS pipe, following through on all plans current and reasonable/additional to fix and load-balance Red+Orange's ability to perform under pressure, and cranking up mainline Worcester frequencies to amplify the effects for MetroWest commuters. That's it. Independent projects that can be mounted without much interdependence or prereqs. And in the case of the UR Brickbottom-Kenmore circuit (if assuming a Kenmore-BU Bridge subway extension with 1 campus subway station and a B Line/UR junction split)...maybe a $450M price tag managed correctly vs. $4B+ for the "East-West Rail Link" dig and surface restoration that no actionable demand data has ever asked for.
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Old 10-15-2018, 11:12 PM   #3391
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Re: Crazy Transit Pitches

I think the Main Street crossing can be grade-separated by elevating Main Street, so that the Grand Junction would stay at ground level.

The following rendering I did shows a bridge in yellow, with ramps on either end touching down at major intersections. The dashed red lines are cross-streets passing beneath. There are no driveways or garage doors needing street access in the ramp areas, so it's physically doable.



For the Broadway and Cambridge Street crossings, maybe the GC rail line could be depressed in a retaining wall cut under those, since those (I think) are a bit inland from the historic filled-in mud flats.

For the Mass Ave crossing, Mass Ave could go in an underpass beneath the tracks. I think MIT planned that at one time.
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Old Yesterday, 02:35 PM   #3392
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Re: Crazy Transit Pitches

As always, your analysis and ideas are a bull's-eyes. Sadly, we live in a region where policy makers, elected officials, and agency leadership can't hit the friggin' dartboard.

A couple of things stick out to me:

Quote:
Originally Posted by F-Line to Dudley View Post
Harbor-crossing on foot/bike to Eastie just isn't going to happen.
People need to stop talking about this as a possibility. As an advocate for the full spectrum of transportation alternatives for the entire North Shore, bridging the harbor is a silly distraction from real solutions.

Quote:
Originally Posted by F-Line to Dudley View Post
You'll get plenty of bikes taken for a ride between Aquarium and Logan stations to get between networks if each side of the Harbor's path network grows out to its fullest.
Absolutely. One of the reasons my ladyfriend purchased a Brompton was to have an easier commute from my place to her office just west of Kenmore.

Quote:
Originally Posted by F-Line to Dudley View Post
Maybe enough to upgrade the Aquarium elevators/escalators for easier bike transport or do up a couple Blue Line cars in the partially seatless "Big Red" setup to facilitate easier bike transport.
I've been advocating a seat-diet for cars 3 and 4 on all Blue Line trains for a couple of years. More floor-space makes sense for bicyclists, Logan-bound travelers with suitcases the size of a dorm room refrigerator, and parents (locals and tourists) with urban assault strollers.

Staying true to the thread's name, my crazy (and unfeasible) transit pitch: Red-Blue Connector at Logan instead of Charles Street.
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Old Yesterday, 05:56 PM   #3393
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Re: Crazy Transit Pitches

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Originally Posted by Charlie_mta View Post
I think the Main Street crossing can be grade-separated by elevating Main Street, so that the Grand Junction would stay at ground level.
That is wildly infeasible. The corner of Main and Vassar/Galileo is wall-to-wall MIT towers. You're going to cut off ground-level lobby access to McGovern Institute, Technology Square, Moderna, Koch Institute, and Broad Institute with a 20 ft. high road deck and inclines??? There's a few billionaires with building namesakes who have a direct line to the MIT trustees to lob some rather firm objections to that plan. No way. On politics alone that's too toxic to handle.



It's important to understand what the real constraints are here, because it's a very different picture by RR vs. rapid transit vs. car modes.

Crossing impacts by-mode
  • Crossings are NOT a problem for RR traffic, because the RR always has the right of way over road at a crossing. Other factors end up conspiring against the RR's performance on the Grand Junction ROW well before the crossing clusters exert any native effect on train traffic.
  • Crossings ARE a problem for road traffic when the RR always has preemption. DTMF switches to keep gates open until train engineer's command are only a partial solution for when a train is stopped at a station platform abutting a given crossing (and, in most cases only helps pare timings in one direction--inbound or outbound--but not the other). Per the Worcester-NS study's official traffic counts Mass Ave. obviously gets clobbered hardest, and Broadway a close second. Main, being a much lower-traffic street than the other two, isn't a huge concern in itself but is shackled to Mass Ave. and Broadway by virtue of the air rights + curve preventing the RR from inclining up/down in time to separate either of the bad crossings.
  • BRT/LRT can direct-share a traffic signal cycle with the road at any grade crossing, solving for the priority issue. In cases like Main/Broadway where the crossings are already at signalized intersections, that means a trolley/bus phase can be grafted onto the existing signal cycles at no more pain than it would take to add a very short protected left-turn phase. This means both Main and Broadway are completely manageable with grade crossings because of their existing signals at very little disruption to any road traffic. It completely eliminates the Broadway queue problems from the RR study by virtue of the mode change.
    • Mass Ave. crossing, being between blocks, would be a mandatory elimination. But since BRT/LRT can climb steeper inclines than RR, also a pretty open-shut case.
    • Cambridge St. is an "it depends" since it's very close to...but not immediately at...the Lambert St. signal. Can easily be done as a double-signal/1.5-queue light if the crossing stays, or eliminated with a carbon-copy transit overpass like Mass Ave.
    • Medford St. is extremely close to the Gore St./Lambert/Twin City Plaza light. Lower-traffic street still, and you might be able to move the signal adjacent to the crossing by reshaping the primary Twin City exit to the last curb cut at the city line and mashing the plaza + crossing into one single signal cycle.

Curve impacts by-mode:
  • The curves ARE the limiter for RR traffic and the GJ's total throughput. The curves at BU Bridge incline, Main St., and Medford St. are each big speed restrictions where there isn't enough straightaway in-between to rev up to speed. Maybe you can hit 35 MPH for a short distance on the Cambridgeport straightaway coming off the bridge, but the combo of Main St. curve + Kendall Station approach + Brickbottom curve + immediate entry into the North Station terminal district upon merging with the Fitchburg Line means not even a nimble EMU is going to be able to rev up much beyond 15-20 MPH for the majority of the trip. This ends up the reason why travel times in the Worcester-NS study were so slow that a subway transfer from BBY-NS or SS-Kendall can do nearly equal time on the off-peaks when the subway is performing normally. The geometry of the ROW is locked-in, so this is unimprovable for the RR mode. With too little room amidst the restrictions for better EMU equipment to positively impact travel times outside the margin-of-error.
  • BRT but especially LRT can take curves faster than the RR can, so there's not a lot of speed restriction involved with a mode change. Nor does hook-in to the GLX Union Branch require as slow a roll into Lechmere as the Fitchburg Line does passing through all the terminal district switches into North Station. Travel times are a lot better with the mode change.
  • Curves are N/A for road traffic on-spec since all crossings here are at 90-degree angles. But that slow zone on RR mode is going to greatly exacerbate gates-down queue backups in the crossings nearest to Kendall where even EMU's have to obey the same speed restriction, and where there'll be too little running room for even an EMU to meaningfully recover enough acceleration before the next crossing.


Sightline impacts by-mode:
  • Sightlines are a problem for road traffic when the RR has perpetual right of way. Main St. would have to have a longer gates-down period because of the blind angle coming off the curve + air rights cover over. Cambridge St. might also need some cautionary padding since there are row buildings massed up pretty close to that crossing. Those streets aren't the bad ones...Mass Ave. and Broadway are...but there's some pain to spread around.
  • Sightlines are LESS of a concern on BRT/LRT when those modes can share a signal cycle. Bus or trolley isn't crossing Main or Broadway until it gets a green phase and the operator looks both ways. No different from any limited-sightline grade crossing of the B/C/E lines. Main's restricted view becomes no problem at all, and Cambridge St. becomes a much safer crossing (consider this if money's tight and you can't swing for full grade separation there).
  • Sightlines are N/A for RR when the curve restriction is the ruling speed penalty. Purple Line would make the same travel time whether those crossings existed or not. Obviously the stopping distance on RR is such that any pedestrian darting in front of the Main overhang while gates are down is going to get smooshed, but that's not the RR's fault.


You get the picture. The dynamics involved are very different by mode. Truth be told, the Grand Junction has been a complete-ass performing railroad for 150 years now...but would be a fan-fucking-tastic light rail ROW with most of the non-Mass Ave. crossing issues totally self-correcting by virtue of the mode change. The sooner we move on from thinking of ways to tart up a born gimp as a RR and start thinking of the stratospheric upside of the mode change, the better.


Quote:
For the Broadway and Cambridge Street crossings, maybe the GC rail line could be depressed in a retaining wall cut under those, since those (I think) are a bit inland from the historic filled-in mud flats.

For the Mass Ave crossing, Mass Ave could go in an underpass beneath the tracks. I think MIT planned that at one time.
The MIT ped plaza idea for sinking Mass Ave. was always a pipe dream. That only appeared on one version of the campus vision plan about 12+ years ago and never since. Kajillion dollars of MassHighway giftwrap for basically a campus vanity project. There isn't enough juice on the Board of Trustees to make such surplus-to-requirement actually happen, and they haven't pretended such since.

It's pretty effortless to incline up/down a trolley or BRT line into an elevated Mass Ave. station here with the huge amounts of side room abutting the crossing on all sides. No need to sink anything...that's hands-down the cheapest. But you can only do it with BRT/LRT because the RR doesn't have enough running room to get back level before the power plant overhang 400 ft. south of the crossing (trolley + wires are short enough compared to RR to still be in the last stages of inclining-down to level as they're passing under the power plant air rights).

No need to sink under Cambridge St. when a carbon-copy template of the Mass Ave. overpass can be done at cost savings by the same contractor. Budgeting isn't done in a vacuum, so buying 2 structure units of one type of construction (overpasses) prices out cheaper than 1 unit of overpass construction and 1 unit of unlike underpass construction.


Broadway can theoretically be overpassed on LRT (but probably not BRT) with a steep incline coming off the Main crossing. Undercutting is going to be a tad too costly because of the landfilled soil remains of Broad Canal on the Broadway-Binney block. RR has nowhere near enough running room to do anything here. Transit overpass would overhang the street only a stone's throw from the existing ped overpass between the Draper and Schlumberger-Doll buildings...so it would fit pretty inocuously into the existing environment and sightlines.

The caveat is that the incline from Main would have to be pretty steep and start very close to the Main crossing in order to get up 16 ft. above Broadway in-time. That's close to the distance the hella steep Science Park incline covers in roughly the same space...but the presence of the grade crossing at the bottom of this incline (or, inversely, at the top of a Broadway-underpassing incline) complicates things a lot if trolleys have to brake-test and/or run at very restricted speed to pack that much rise that close to a signalized crossing in fail-safe fashion in any type of weather. We can't speculate about the ops side-effects today with only Google Maps to look at; the transit engineers have to have their say. Just assume it could go either way on coin-flip odds. If presence of an incline ends up inducing a mandatory slow crawl that risks a mid-line performance clog, you're better off just keeping both crossings and tweaking the signal phases. Then, spending the money you would've spent overpassing Broadway on overpassing Cambridge St. instead.
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Old Yesterday, 09:36 PM   #3394
Deetroyt
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Re: Crazy Transit Pitches

F-line, what about Binney St? Would they likely put in an overpass if they overpassed Broadway? Or is this crossing not an issue?
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Old Yesterday, 09:55 PM   #3395
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Re: Crazy Transit Pitches

F-Line, I agree about elevating an LRT line on the GC over Mass Ave, Cambridge Street and Broadway. If done right these could look pretty decent with landscaping, architectural treatments of the structures, etc.

Main Street bridging over the GC tracks is probably NIMBY toxic as you say. My real preference is to simply block off Main Street from crossing the tracks here. I don't care about the traffic backups that would happen as a result. I'm much more concerned about the impact of Portland Street increased traffic upon the quality of life in the Newtowne Court housing project. So, we are stuck with a grade crossing at Main Street for an urban ring LRT on the Grand Junction. But that is not a big deal as you pointed out.

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