Crazy Transit Pitches

[F-Line to Dudley]

Main St.'s not an eliminable grade crossing. Plowing deep under the Red Line and under the water table isn't going to be feasible. Check the 1902 topo map on Historic Aerials. The Grand Junction from Main to BU Bridge was the riverbank until the landfillers filled out to create the Basin's wall in advance of the dam's 1910 opening. The only reason they had an easy time building the Red tunnel is because the whole area was empty and had no under-street utility layer to cut under. That's why Kendall station is so shallow vs. the level of the portal. So unfortunately there's a cost-with-depth waterproofing pain threshold that gets exceeded before you've successfully slipped under Red. GJ will always have to be on a mode suited to taking a grade crossing.

 

[vanshnookenraggen]

But where is the water table today? Is this an area prone to flooding? Isn't part of the problem with foundations for older buildings in the Bay Village and South End collapsing because the water table there dropped? Perhaps the water table here is lower than it was 100 years ago.

I'm not saying it would be cheap but given how quickly Kendall is filling up with development and that the state may very well implement CR service over the GJ I can see the day when it is politically advantageous to build a tunnel here to eliminate grade crossings. The need for better transit through this section of Cambridge is growing by the day and at some point the cost becomes worth it. Grade crossings will kill any form of rapid transit here even if it's just more CR.

Hell, if you build the tunnel strong enough you can offset the cost by selling the air rights to MIT. With a subway station, no grade crossings, and larger building footprint this area (which is now home to old facilities, repurposed warehouses, and garages) could be the next place to build out when Kendall fills up. The potential for economic development along the GJ can justify the cost.

 

[citylover94]

Just to demonstrate how the Grand Junction as light rail could help with load spreading and act as a third main line section with some of the reconfigurations that have been discussed I created this map: http://goo.gl/00cBZb

I don't think grade crossings will kill this proposal as the rail line would just flip the traffic lights at the crossings to red lights when the train goes through although it might limit frequency somewhat.

 

[F-Line to Dudley]

But where is the water table today? Is this an area prone to flooding? Isn't part of the problem with foundations for older buildings in the Bay Village and South End collapsing because the water table there dropped? Perhaps the water table here is lower than it was 100 years ago.

I'm not saying it would be cheap but given how quickly Kendall is filling up with development and that the state may very well implement CR service over the GJ I can see the day when it is politically advantageous to build a tunnel here to eliminate grade crossings. The need for better transit through this section of Cambridge is growing by the day and at some point the cost becomes worth it. Grade crossings will kill any form of rapid transit here even if it's just more CR.

Hell, if you build the tunnel strong enough you can offset the cost by selling the air rights to MIT. With a subway station, no grade crossings, and larger building footprint this area (which is now home to old facilities, repurposed warehouses, and garages) could be the next place to build out when Kendall fills up. The potential for economic development along the GJ can justify the cost.

You're going to have to ask some MIT nerds about that one. It's waterproofing megabucks for sure because a tunnel with 100-year engineering lifespan in the Basin on an old shoreline has to account for unpredictability at the century level in the water table. A lot of the state reports (incl. some gobbledygook on the City of Cambridge website) about the Basin's flood susceptibility cited the drop in water tables on the Boston side as a problem to be rectified by increasing the absorption rate of the ground. Stuff as inocuous as vegetation and soil management to dredging out long-buried underground streams and aquifers so they're still underground but flowing instead of haphazardly choked.

That's the sort of stuff you have to engineer for with a 100-year tunnel. And the stuff City of Cambridge says going to be necessary since an 8-inch overtopping of the dam puts Kendall underwater. If the expert analysis says they have to exploit more absorption in what's already pretty soggy fill, plot your expenses accordingly. It is going to be, even at its most benign, an un-ordinary amount of waterproofing you would have to do here to burrow under the old shoreline for that long a stretch.


Is this accomplishing that much above-and-beyond LRT with one...maybe two total grade crossings that can't be bridged? This is, after all, a linear ROW boxed in to property lines 50 ft. or less wide over most of its distance. It's not, like, countable as square footage of real estate. The wide section from Mass Ave. to Memorial Dr. was mostly one long set of private freight sidings behind the factory buildings' loading docks. If the rail-with-trail doesn't claim it beforehand the properties will encroach out to the T's 2-track easement when MIT nukes them. Just like it did everywhere else. The remains of the Cambridgeport freight yard, Waverley St. street-running track, and associated sidings all got obliterated in the last 12 years by new development. The juiciest parcels at the juiciest points on the street grid have already been covered over. Most of the next-juiciest will be covered over by MIT before you even get to commission a scoping study. The rest is all behind other buildings, non-interfacing from the street. It's not the Pike air rights; the Pike air rights are flanked by a street grid the entire way. It's a transit service, not a rental office.

 

[F-Line to Dudley]

Just to demonstrate how the Grand Junction as light rail could help with load spreading and act as a third main line section with some of the reconfigurations that have been discussed I created this map: http://goo.gl/00cBZb

I don't think grade crossings will kill this proposal as the rail line would just flip the traffic lights at the crossings to red lights when the train goes through although it might limit frequency somewhat.

It really won't. The whole problem commuter rail has is that train has priority 100% of the time. So no matter when it arrives, how often it arrives...gates go down, traffic stops. That's the rules by an FRA railroad, and that's what screws up all the traffic queues on these streets.

Light rail follows traffic signals. Since the Main and Broadway crossings are right at traffic lights, you simply program it with trolley priority. As if the trolley is getting a protected left. On Main that may involve moving the stop line back 80 ft., but otherwise it's the same: a normal light cycle that has greens as long as Broadway and Main would ever have.

Mass Ave...you eliminate with an overpass. The others: ration according to funding, with Cambridge St. a #2 priority (if it's absolutely not possible, the crosswalk light at Max St. can probably be shifted 70 ft.).

 

[cozzyd]

Because of the way it doesn't quite go to either Central or the Longfellow, Main St is not really a major road for cars. It be severed at that intersection without great loss as long as it's possible for pedestrians and bicycles to cross. Pedestrians can have escalators over an at-grade heavy rail station station and I think there's enough room to build a bicycle overpass or underpass...

 

[F-Line to Dudley]

Because of the way it doesn't quite go to either Central or the Longfellow, Main St is not really a major road for cars. It be severed at that intersection without great loss as long as it's possible for pedestrians and bicycles to cross. Pedestrians can have escalators over an at-grade heavy rail station station and I think there's enough room to build a bicycle overpass or underpass...

I don't think you even need to sever it. A trolley or even BRT fits snugly into a regular signal cycle, and you would want the cab stand and bus dropoff space on a curb jut behind the intersection because that weather-protected air rights overhang is the best place to plunk the platforms. On that street the signal wouldn't matter if you added a delay for the trolleys given the volumes or lackthereof.

For similar signaling reasons much busier Broadway isn't a concern on LRT or BRT. Their signal cycle can be exactly the same length/timing as today in the busier Broadway direction. If there's any trolley priority to install it's a delayed green on far less busy, multi-lane, curb cut-free Galileo Gallilei. Broadway and Galileo I believe are already no-turn-on-red (Galileo definitely is) in their dedicated right-turn lanes, so that safety + trolley priority installation isn't needed and wouldn't induce any additional delay between signal cycles since the NToR protection on rights is pre-existing.

It's as a RR where FRA rules mandate absolute 100% train has right-of-way at all times where the traffic gets disrupted. That's why if this corridor works at all as Indigo (and that's real dubious), that's only a stopgap solution for what eventually has to happen on some other mode that can deliver the headways ultimately needed.


Order of priority for crossing eliminations pretty much goes like this if you're doing a mode conversion:
-- Mass Ave. (mandatory)
#2. Cambridge St. (At-grade + shift ped traffic light only if too strapped for cash to eliminate immediately.)
#3 or #Last*. Binney (Close/ped plaza it, banning all but delivery or service vehicles. *If ped plaza option not preferable, leave it for last or don't eliminate at all because volumes are lowest here of any crossing.)
#4. Medford St. (Ample space for elimination, viaduct/embankment would help 2-for-1 Cambridge St. if you've got the money and the patience to deal with crabby residential abutters. But kick behind Binney on the priority order if the Binney closure option works.)
#5. Broadway (Possibly eliminable on trolley where the inclines from an overpass can be steeper to make it back to grade by Main, but definitely too steep for BRT. Eliminate last despite traffic levels because other eliminables don't have nearly as ops-ideal a signal placement as here.)


Of course, as RR none except the Binney plaza concept (which probably isn't worth doing at those headways) are eliminable because the maximum grades just don't allow enough incline room between crossing pairs. Especially on the Main-Mass Ave. block where the air rights pinch nearly all the running room for a 1-2% incline.

 

[cozzyd]

The reason I proposed severing Main St. is to allow HRT as Van and others have suggested.

I like the the idea of having the blue line go under the Charles, cut and cover under Binney (with stop at 2nd or 3rd), and then follow the GJ to Allston.

 

[George_Apley]

Do any cities have at-grade HRT in a central business district? I know some systems have them in more far-flung areas, but that seems fundamentally different to me.

 

[bigeman312]

Do any cities have at-grade HRT in a central business district? I know some systems have them in more far-flung areas, but that seems fundamentally different to me.

It probably depends on your definition of "central business district" and your definition of "at-grade." Haha. Does a trench count? How about an embankment? In NYC, what counts as the "central business district?" Only Midtown and Lower Manhattan? All of Manhattan? Do you count Downtown Brooklyn?

EDIT: I ask because I can think of multiple examples of the NYC Subway occupying a trench in dense parts of Brooklyn.

Double EDIT: The DC Metro Red and Blue Lines both runs at-grade through parts of Northeast DC, which is not exactly in the central business district.

Triple EDIT: Many of the Chicago "L" Lines run both at-grade (especially in the median of highways) and on an embankment in parts in the North Side, South Side, and West Side (not the CBD, but certainly close in neighborhoods of the city. Not unlike JFK/UMass).

Honestly, you probably won't get much closer than the section of the Orange Line (MBTA) that runs along the Pike between Back Bay and Tufts Medical Center.

 

[Matthew]

The "L" has about a dozen grade crossings of third rail on the Pink, Brown, Purple, and Yellow lines that I observed personally. At busy roads. Yeah, not in the core, but traffic is even heavier in the suburbs generally. Not that I ever expect the USA to ever build a third rail grade crossing ever again.

But probably the most famous grade crossings are in Japan. I believe there is a crossing in Tokyo on the Yamanote line that can only open for a sum total of a few minutes every hour due to the intense train traffic.

 

[cozzyd]

Do any cities have at-grade HRT in a central business district? I know some systems have them in more far-flung areas, but that seems fundamentally different to me.

Airport Station is probably the closest thing on the T. The idea would be to build a pedestrian plaza above the station changing the effective ground level for pedestrians, but the approach might be a little tight on the MIT side.

 

[bigeman312]

I see! You are wondering about rapid transit grade-crossings in a CBD. That is different from how interpreted your question. Ya...probably doesn't happen.

 

[F-Line to Dudley]

I see! You are wondering about rapid transit grade-crossings in a CBD. That is different from how interpreted your question. Ya...probably doesn't happen.

All of the ones CTA has on the L's Brown, Yellow, and Pink lines are all legacy installations slowly declining in number and reduced to pretty much the toughest holdouts. They're protected out the wazoo and CTA pays some steep insurance premiums on theirs. If they had the wherewithal to do 100% eliminations without each one having big cost/pain threshold, they would've done it by now.

Even NYC Subway had grade crossings until the last one was eliminated in Brooklyn in 1975. The T considered building the extension of the Orange Line to Reading with some of the Western Route's 13 grade crossings remaining and a Blue Line-like switch from 3rd rail to overhead at Oak Grove. It's why they ordered the same make of cars of Blue and Orange; the Orange 01200's have pantograph hookups on the roof that can plug-and-play with one of the pantographs off a Blue 0600 car.

But that was late-60's/early-70's when it was in planning; by the time it was actually built they'd truncated to Oak Grove because of Melrose NIMBY's. And in that span NYC had fully grade separated, and CTA had sharply reduced its remaining count...removing the "other cities do it" justification that would've kept their insurance liability in-check. It'll never ever be allowed today. Unlike low-to-the-ground LRV's, commuter rail locomotives, and commuter rail cab cars with their permanently mounted snowplow blades heavy-rail subway cars are too exposed on the underside and don't demonstrate the "cowcatcher" effect when hitting something on the tracks...i.e. the obstruction gets pushed ahead of and away from the train. It's why when somebody commits suicide-by-train on Red/Orange/Blue they get pinned underneath instead of being launched up or forward. Make that hit on a grade crossing a car or truck instead and you add the risk of the heavy-rail car telescoping off the tracks when the obstruction gets pinned underneath.

See for yourself:

HRT (note height of underside, and coupler acting as the only protection):

LRV (with idiot's truck for reference):

Locomotive:

Cab car (note the plow blade; comparably a little more vulnerable at a crossing than a loco or LRV, but still heavy enough to push in a collision):

It's freak-accident odds, to be sure...but it's enough of a risk that there'll never ever ever be a new installation. Nor is the T ever going to start ordering heavy-rail cars deviating from 105 years of rote-generic design and switch over to carbodies shaped more like a commuter rail EMU to get the full cowcatcher effect.

You really, really have to demonstrate that full 100% grade separation and HRT matters that freaking much to spend a billion dollars on separation--and waterproofing of said separation--here, vs. LRT where every crossing except Main is eliminable. The performance difference has to be worth $1B in additional ridership revenue on a 6-car heavy-rail train vs. a 4-car light rail train to even think about subwaying here. And I can't conceive of a scenario where that difference neutralizes the cost. You could probably spend the same amount of money on light rail capacity increases elsewhere and get better throughput here than the perfectionism of full HRT burial. Every bit of air rights property fiscally worth MIT's while to build over will be built over the surface ROW. That sure as hell isn't going to be a revenue driver narrowing the gap.

This is a more obvious call than most.

 

[George_Apley]

Back to Lex for a moment. Assuming that someday Red is able to get through Lexington through a combo of surface running and selective tunneling via Minuteman, where would the Hanscome/I-95 station be sited? Behind the Hartwell Ave developments in Tophet Swamp? Would that require new ramps off of 128? Or would it go closer to Bedford Street and be accessed via the existing 128/225 interchange?

 

[BostonUrbEx]

Ok, seriously guys, can we have a chat?

Why on Earth do we keep talking about a rapid transit extension through a low-density area which couldn't even support commuter rail? Out of all the viable rapid transit extensions, I feel not a single one is ever talked about more on this forum than a Red Line North extension. Red to Waltham is more viable than that. The horse's decomposed remains have been beat into dust, and the dust was beat until it dispersed and blew away in the breeze. And then it was beat some more.

 

[vanshnookenraggen]

Back to Lex for a moment. Assuming that someday Red is able to get through Lexington through a combo of surface running and selective tunneling via Minuteman, where would the Hanscome/I-95 station be sited? Behind the Hartwell Ave developments in Tophet Swamp? Would that require new ramps off of 128? Or would it go closer to Bedford Street and be accessed via the existing 128/225 interchange?

No. All of the No. Just No.

 

[F-Line to Dudley]

Ok, seriously guys, can we have a chat?

Why on Earth do we keep talking about a rapid transit extension through a low-density area which couldn't even support commuter rail? Out of all the viable rapid transit extensions, I feel not a single one is ever talked about more on this forum than a Red Line North extension. Red to Waltham is more viable than that. The horse's decomposed remains have been beat into dust, and the dust was beat until it dispersed and blew away in the breeze. And then it was beat some more.

Per the most recent estimates (2003 PMT) they crunched +6700 daily weekday riders on the Red Line and +1700 daily weekday riders not currently taking any form of transit. That's not chopped liver, and either extreme--"WE NEED THIS NOW!" or "IT'S A DEAD HORSE!"--is a bunch of shrill histrionics.

It's low-rated overall because it's the most end-to-end miles of any rapid transit extension and the capital cost per rider is going to be a bitch because of the mileage. And you need to have a winning development strategy for Hanscom before before dragging it all the way out there. That doesn't exist today. The talk about Boston needing a second airport is premature, and it's a long ways away from being an employment anchor. But that's why you frame this as TWO separate extensions: Heights, and Hanscom. Nobody treats Blue to Salem as a monolithic build out of Wonderland despite the new transit ridership and cost-per-rider on the stations past Lynn being better than to Lynn. For simple fact that Lynn has other pressing needs, and one foot has to go before the other. This one shouldn't be treated that way either. That's just its legacy because it happened to be the last thing formally studied in an era that couldn't be more different than today.


It's 1.5 miles of shallow box tunneling that restores the Minuteman to as-is condition, and 1 subway stop. That's non-controversial and a non-backbreaker. It's 1.5 miles of preferably surface routing with shifted trail, less-preferably a combo of some surface and some cover-over around abutters. At a third the total distance to Hanscom and only 2 of the 5 stations specced for an extension to Hanscom, Height's per-rider capital and operating costs more or less hit the league average for the much better-hyped Orange/Blue extension proposals. So don't be absolutist and lump the two builds together, and don't treat it as off-scale with similar extensions. It's not off-scale.

Demand for Heights has been established since 1945, is growing acute with Mass Ave. congestion, will grow more acute when GLX gets to Route 16 and generates still more rapid transit demand in Arlington...and they have some degree of non-buyer's remorse about turning this down in the 70's when it was there for the taking at more favorable cost. You can't blithely assume the 1.5 miles miles past the High School will be nuked from orbit without attempting to negotiate. So neither be absolutist nor lump it in with Hanscom, which is a future-not-present tense growth prospect.

Lex isn't ready for it. Hanscom definitely isn't ready for it without some sort of compelling master plan. We don't know if either will ever be ready for it. We also don't know how Lexington would utilize it, since Alewife is 6 miles away from Lexington Center and virtually unreachable because of congestion and multiple required bus transfers while Heights would be a fast transfer. You also can't assume the first leg doesn't serve and draw Lexington ridership. So don't be absolutist.


OK? That's not unrealistic. Whether you would rank it in your Top 5 system expansion priorities is up for debate, but hyperbole...no. That's as useless at either extreme.

So is comparing it to commuter rail that ran one round trip per day in 1977 on equipment so shot it had with par odds of not making it to destination...run by an operator in its 7th year of bankruptcy reorganization. It is a bunk, hysterical comparison.

And Red to Waltham as icing-on-cake for a hyperbolic statement about Arlington/Lexington is equally useless. You can't physically get out of Alewife in that direction without blowing up the Pfizer campus, and you probably can't eliminate the Waltham Ctr. grade crossings with the bridges immediately east constraining the incline room and the Charles 100 ft. away most definitely making a cut no-go. LRT out of Union/Porter is probably the only extensible mode out there. That's a whole separate argument, but using that as the basis for a hyperbole indictment of Red extensions is likewise...a bunk, hysterical comparison. Waltham has absolutely zilch to do with a Red extension.

 

[F-Line to Dudley]

Back to Lex for a moment. Assuming that someday Red is able to get through Lexington through a combo of surface running and selective tunneling via Minuteman, where would the Hanscome/I-95 station be sited? Behind the Hartwell Ave developments in Tophet Swamp? Would that require new ramps off of 128? Or would it go closer to Bedford Street and be accessed via the existing 128/225 interchange?

No new interchanges...definitely not necessary. It's a typical ridiculously overbuilt Massachusetts cloverleaf with the local road spreading to a gargantuan 4 lanes around the interchange.

I would assume it probably skirts most of the wetlands by taking what's now parking lots whenever it deviates off the Minuteman. Probably a storage yard on the Lexington composting facility yard and stub station either along Maguire Rd. behind the Mass General Autism Center, or taking a sharp right into the rear Hartwell Ave. lots behind Children's Hospital with more direct park-and-ride access at Route 4. Reliable assumption that this area will have grown explosively enough to take some of that asphalt parking and have made it vertical parking by the time this is built. So wetlands probably aren't that big an issue despite the ROW being surrounded by 'em on that side of 128. 99% of the deviation off the old railbed is on present-day asphalt any way you angle it for the station stop and storage yard.

 

[George_Apley]

No. All of the No. Just No.

Thanks bro...

For the record, I am not beating the drum for a RLX to Lexington (I am for Arlington Center ASAP though). Kind weird to have people who have proposed all kinds of crazy transit pitches jumping all over a question regarding a someday in the future possible extension of the Red Line to 128/Hanscom/Burlington. Settle down boys.