I-90 Interchange Improvement Project & West Station | Allston

[jklo]

It's a long outage, but won't run anywhere near the whole duration of the project because the touches in that area are a subset.

But it's sort of a critical part - the tracks are underneath the aqueduct.

My understanding is that the Worceter Line is going to be single track for a good long period too.

 

[whighlander]

Least -- I be accused of derailing the thread or worse adding to the discussion -- this post is designed to "Pick some Nits" which I've noticed in reading the past dozen or so posts

Let's start with the easiest -- Say Via-Duct as opposed to Aqua-Duct -- one is an elevated thoroughfares for people and vehicles [as in Via Appia] the other is a path for water

Now one which I was genuinely surprised at seeing from F-Line who is generally quite thorough in his railway engineering
F-line in discoursing on the GJ in Cambridge said about grade crossings:
The only one which needs to be grade separated is Mass Ave.
he further stated that Binney St. could be closed
and he further ignored the major crossings at Main St. and Broadway

I think the property owners and developers at or around those streets would have a substantial objection to digging under Mass Ave and then crossing Main and Broadway at grade. Closing Binney might be an issue given the development potential at its junction with Galileo Way now that Metropolitan Pipe is gone.

Essentially -- I think that if you tunnel for Mass Ave the tunnel has to continue until Schlumberger / Draper at least.

 

[Deetroyt]

I think the idea was to have it run on a viaduct above Mass Ave. rather than digging below, but i could be wrong. F-line has described why tunneling under Main isn't feasible due to the red line running beneath.

 

[F-Line to Dudley]

I think the idea was to have it run on a viaduct above Mass Ave. rather than digging below, but i could be wrong. F-line has described why tunneling under Main isn't feasible due to the red line running beneath.

It's infeasible because everything west of Main is on 1905 landfill and then you have to underpin Red while rounding a sharp curve. The infeasibility is the whole mile of soft fill that has to be active-waterproofed, and then the need to protect Red from being fucked by the "storm drain" effect: any catastrophic breach draining down into the lower-level tunnel imperils the Red tunnel that today isn't in any flooding danger.

Waterproofing alone is a billion-dollar cost bloater, and why you can't count on tunneling costs from the Boston side of the river (no waterproofing under Comm Ave. or Mountfort) to translate to the Cambridge side. It's no-fooling 2x the cost to build the same tunneling feet and underground stations on that side. More than twice if it's somebody's idea of a kooky RR-mode "East-West Rail Link" because the bore has to be so much bigger and the inclines so much longer on that mode (on the same dog-ass slow speeds over the sharp curves).

It's impractical in the extreme to tunnel over there. Especially when surface LRT/BRT with shared traffic signals at the non-eliminable crossings does 98% of the job at 1/10th the price. There's no value proposition in burying ANYTHING on that side.

EDIT: Yes, Mass Ave. is a simple overpass on LRt/BRT. You just can't do that on RR mode because there's not enough room to incline at allowable grades between the MIT power plant overhang and the crossing. If you want that one gone, pick literally any mode except RR and it's gone lickety-split.

 

[F-Line to Dudley]

Least -- I be accused of derailing the thread or worse adding to the discussion -- this post is designed to "Pick some Nits" which I've noticed in reading the past dozen or so posts

Let's start with the easiest -- Say Via-Duct as opposed to Aqua-Duct -- one is an elevated thoroughfares for people and vehicles [as in Via Appia] the other is a path for water

Now one which I was genuinely surprised at seeing from F-Line who is generally quite thorough in his railway engineering
F-line in discoursing on the GJ in Cambridge said about grade crossings:
The only one which needs to be grade separated is Mass Ave.
he further stated that Binney St. could be closed
and he further ignored the major crossings at Main St. and Broadway

I think the property owners and developers at or around those streets would have a substantial objection to digging under Mass Ave and then crossing Main and Broadway at grade. Closing Binney might be an issue given the development potential at its junction with Galileo Way now that Metropolitan Pipe is gone.

Essentially -- I think that if you tunnel for Mass Ave the tunnel has to continue until Schlumberger / Draper at least.

No, nothing was "ignored" The grade crossing impacts have been extensively discussed in many UR-related posts you apparently couldn't be bothered to read, and were quantified with real car counts in one of those studies you claim to have sort-of-but-not-really read. It's rather quite impossible to have truly kept up on UR discussion on aB over the years and not gotten a whole lot of crossing info to chew on. But thanks for the ad hominem anyway! Staying completely in character even while offering a half-hearted olive branch, I see.

---------------

Let's spell this out, if you're in an actual reading mood today. . .

Main St. and Broadway can't be eliminated on any mode. The Main St. overhang prevents it there, and the incline space on the Main-Broadway midblock for attempting to eliminate Broadway is so short that a maximum-steepness trolley incline with a traffic light at the bottom would be a self-defeating speed restriction clog. The 2012 MassDOT Grand Junction Transportation Feasibility Study calculated traffic impacts from RR gate timings on an upgraded line for purpose of running 5 A.M. peak and 5 P.M. peak unidirectional Worcester-North Station trains. Clicky the linky and they've got all the separate AM & PM peak-period traffic counts, ped counts, and bicycle counts with directional splits at each grade crossing. Negative impact was calculated via the default gate timings, with assumption of signal reprogramming for queue dumps after a train had passed. Though they have not fed these numbers into the RUR plan for 15-min. bidirectional frequencies, you can ante-up from the Worcester study numbers to isolate the problem areas.

Now, the big advantage BRT/LRT have is that they can share road signals while RR cannot. RR always has absolute priority, which is why the traffic signals on the RUR plan can only be reactive instead of proactive at dumping a queue around a train. In a nutshell, that's why the RR mode is the crummiest choice by far for any increased frequencies on the corridor. It's also why Mass Ave. is such a must-eliminate; the crossing is at the midpoint between traffic signals and ends up hosing two intersections at once with few mitigation options. Main and Broadway, on the other hand, have the stop line for their signals immediately abutting the tracks...very advantageous for signal programming. A trolley or bus phase can be grafted onto the existing signal cycles as if it were just another turn phase or crosswalk phase. This greatly minimizes the impact by allowing transit crossings to fold inside of an existing direction's cycle.

So say at 6 min. bi-directional headways it takes a 20 second transit phase for a trolley or bus to reliably clear the crossing. 20 secs × 2 directions every 6 min. window means the transit phase is *somehow* (but not absolutely) affecting other traffic for a maximum of 40 out of every 360 seconds. Then subtract time for all vehicles that clear in < 20 secs., as the transit phase will be programmed to cut short after an early clear. Then subtract more for dispatch coordination of eastbound/westbound vehicles to pass simultaneously when possible to minimize the footprint of the transit phases. Station placement also matters: is there going to be one mid-block Kendall stop sandwiched between Main-Broadway, or 2 flanking stops...one under the Main St. air rights within eyesight-wayfinding of the Red Line station, and one at Binney St. anchoring the other side? That will inform what dispatching tricks are used for timing moves through the signal phases (personally, I think the 2 flanking stations work better for high-precision timing because the station dwells can be leveraged vs. signal phase windows). All of ^these^ considerations feed into choice of signal phasing.

OK...so now you figure out how to divvy the phases. Direct study comparison with other LRT and BRT systems is obviously a must for how they handled phasing on similar-makeup intersections; there are plenty of examples to choose from. Probably the most straightforward way to handle is to overlay the transit phase on the green for Galileo Galilei Way, and to make all southbound right-hand turns from Galileo protected-right signaled mirroring the left-turn signals.

• Galileo @ Broadway is already set up exactly this way with right-lane = right-turn only, No Turn On Red, protected-right arrow signals, and an extened right-only green phase that lingers when thru + left are red. Perfect! Nothing to do here except re-time the protected-right to fit the 20 secs-or-less transit phase.
• Galileo @ Main lacks the dedicated right-turn lane of the Broadway intersection, so has a permissive right. Simply replicate the Broadway setup verbatim here by adding that right lane and mirroring the signal setup. The little parklet on the corner has ample space to give for adding that lane.
• Main would need its stop line moved back a bit, and if LRT tracks would be re-angled into a sharper curve at the crossing so the crossing distance isn't as awkwardly far from the intersection. It's currently a 150 ft. difference, but the track re-angle can probably split that difference to about 100 ft. Signals would have to be re-timed there just for clearing the intersection from the further set-back stop line. Broadway needs no modifications whatsoever. Signal phases would stay the same here, but would have queue dump programming for the transit phases jumping all over the regular signal churn.

Now...you take the car/bike/ped counts from the Worcester study, do some moderately complicated but layman's math to plug the transit phase breakdown in place of the RR gate timings, and you tally up a quantified traffic impact. You can probably Google up some MUTCD info on phasing best-practices to help with that and better-visualize what's going on. I am not in the mood on a rainy Mon. evening to attempt anything more than rudimentary arithmetic, so you're going to have to show yourself the math. But you can indeed do it with the publicly available counts.

It does not--with all the available phasing tricks in the book--add up to a carpocalypse at Main & Broadway even with brisk 6 min. headways. Way, way not-a-carpocalypse. It's solid...very solid. Moreso because all LRT/BRT options assume Mass Ave. crossing being eliminated meaning Main is under a little less stress from the Central Sq. direction. Given that the existence of such rich headways likely takes car traffic OFF those roads, City of Cambridge is not going to have a problem with the 6-min. headway LRT or BRT build options. Not like they would with the 15-min. headway RUR option where absolute gates-down priority makes traffic recovery afterwards an order of magnitude harder.


As for the others...Binney isn't in the same universe to begin with, so the scope of any debate about whither closing it is not exactly the stuff of high-stakes politics. If there ends up preference for 2 flanking instead of 1 consolidated station you're probably siting the northerly stop directly at Binney and closing the crossing just to turn it into the station plaza, where ped/bike crossing will be allowed but cars no more. Cambridge St. has an existing ped crossing light at the crossing for the large Cambridge Housing Authority Millers River Apartments tower. Unless you've got tons of extra money burning a hole in pocket for a bonus elimination, just appropriate that light for the at-grade transit phase. I mean, even with an elevated station the ped signal is going to get used way more anyway by users of the station...so there ends up little difference between projected baseline ped crossings causing red lights vs. corralling most of those pedestrians inside a regularly-occurring transit red phase. If there's any elimination to ponder there it's one you do years later when funds permit and not as an extra moving part on the base build. Medford St. is a low volume non-concern.



You wanted some specific answers? ^^Here^^ they are. Keep the TL;DR to yourself this time if seeing it spelled out is more boring than watching paint dry.

 

[whighlander]

F-Line when your posts are about transit construction / operation -- I read them carefully as you are a good source of technical information
When your posts veer into other areas -- your imprimatur is not quite so strong -- so reading get's relegated to when / etc.

I would caution that because the crossing of Mass Ave is so intimate for MIT -- that you would not easily get MIT to want a viaduct running along the Vassar Strip -- MIT would definitely rather want a tunnel and perhaps a grade crossing as next alternative

 

[F-Line to Dudley]

F-Line when your posts are about transit construction / operation -- I read them carefully as you are a good source of technical information
When your posts veer into other areas -- your imprimatur is not quite so strong -- so reading get's relegated to when / etc.

Well, I can't help you there. If you keep intentionally misrepresenting facts solely because you find them too personally boring to read...that's entirely your problem, not mine.

I would caution that because the crossing of Mass Ave is so intimate for MIT -- that you would not easily get MIT to want a viaduct running along the Vassar Strip -- MIT would definitely rather want a tunnel and perhaps a grade crossing as next alternative

Again...you are not burrowing under porous 1905 Charles Basin fill for less than a kajillion dollars because of the required waterproofing premium. Be it in a tunnel or partially open-cut . It blows the cost valuation out of the water, and the closer you have to trench that incline to Main St. (and you will be trenching that incline all the way to the curve if these are RR grades) the closer you are to putting the dry Red Line tunnel under peril from the 'storm drain effect' of dredging an accidental canal to its doorstep. Netherlands-grade waterproofing or GTFO, as it were. That is a cost murderer for any transit project on the corridor vs. any permutation of at-grade or elevated (n.b.: LRT/BRT-only). It will never happen. It does not matter what MIT visually prefers. They are not getting a burial, only (A) at-grade, (B) elevated, or (C) no change at all from present conditions and thus no transit line at all. And since they and their endowment are primary beneficiaries of rapid transit conversion, I much doubt the Board of Trustees are willing to look (C) in the face as an acceptable final answer for themselves.

Even their own campus master-plan renders from a dozen years ago of a Cambridge Common-style Mass Ave. burial under the Vassar/Albany blocks (with tracks at-grade and crossing remaining for only the very low-volume one-way frontages to the Vassar/Albany intersections) is going to be virtually impossible to construct at acceptable cost for the same porous-fill waterproofing reasons. And they were expected to put their own money towards that MassHighway effort once upon a time. Since there's been virtually zero mention of it in any of the years and any of the master-plan revisions since, it's pretty clear they quickly found out how much of an engineering overreach the initial render was.

If this thing gets built, there'll be a simple low-profile overpass of Mass Ave. Station siting can be adjacent to one side or the other to minimize the track profile over the road-proper. Emphasis: overpass, not "viaduct". Per the T's own light rail design manual max grades on an incline are: 4.0% sustained, absolute 6.0% max for 2500 ft. length tangent track segments bookended by flat tangent sections. Per their BRT design manual for busways it's 5.6% in the open, and 0.5% on any switching points built to accommodate LRT conversion (i.e. Transitway turnouts only). On the RR design guide it's 1.5% max incline grades for new construction with *specific* FRA waivers only (such as: Wellington tunnel @ 3.5%, waivered for future Orange Line conversion; 3% for Mystic River Bridge on Eastern Route + Neponset River Bridge on Old Colony, waivered as fixed replacements for former draw spans over maritime-regulated water clearances).

You can do some awfully quick climbing from at-grade to 16 ft. state highway clearance over road with 4-6% grades. If the Mass Ave. LRT/BRT station were stacked on the less visually appealing power plant side of the crossing you could do the platform and get down under the overhang on trolley...then get down on the ground on the other side before even reaching the back side of the Metropolitan Storage Warehouse building. It's not visually impactful at all. RR...forget it. You don't have anywhere near the room between Mass Ave. and the plant overhang to do the climb at 1.5% grade on that side so it's 100% impossible right then and there. On the other side, even if you could you'd need 1067 ft. of incline room...putting you at midfield of the football stadium before reaching flat ground. Now thats visually impactful. It's no contest. Not only can Mass Ave. only be eliminated one way: by air with LRT/BRT, and never--on any mode--below because of the water-proofing blowouts...but any/all eliminations you do do would cost a fraction as LRT/BRT vs. what they would on RR.

MIT is not going to get bent out-of-shape about this when the benefits of building rapid transit with an aerial crossing elimination can be counted in $$$ gains to their endowment when any aesthetic objection either nets them crappier at-grade transit with worsened congestion or nothing at all...immediately countable by the Board in passed-up $$$ to their endowment growth. To them the bottom line impact is immediately FAR more compelling than the non-issue aesthetic nitpicks.

 

[whighlander]

Well, I can't help you there. If you keep intentionally misrepresenting facts solely because you find them too personally boring to read...that's entirely your problem, not mine.



Again...you are not burrowing under porous 1905 Charles Basin fill for less than a kajillion dollars because of the required waterproofing premium. Be it in a tunnel or partially open-cut . It blows the cost valuation out of the water, and the closer you have to trench that incline to Main St. (and you will be trenching that incline all the way to the curve if these are RR grades) the closer you are to putting the dry Red Line tunnel under peril from the 'storm drain effect' of dredging an accidental canal to its doorstep. Netherlands-grade waterproofing or GTFO, as it were. That is a cost murderer for any transit project on the corridor vs. any permutation of at-grade or elevated (n.b.: LRT/BRT-only). It will never happen. It does not matter what MIT visually prefers. They are not getting a burial, only (A) at-grade, (B) elevated, or (C) no change at all from present conditions and thus no transit line at all. And since they and their endowment are primary beneficiaries of rapid transit conversion, I much doubt the Board of Trustees are willing to look (C) in the face as an acceptable final answer for themselves.

Even their own campus master-plan renders from a dozen years ago of a Cambridge Common-style Mass Ave. burial under the Vassar/Albany blocks (with tracks at-grade and crossing remaining for only the very low-volume one-way frontages to the Vassar/Albany intersections) is going to be virtually impossible to construct at acceptable cost for the same porous-fill waterproofing reasons. And they were expected to put their own money towards that MassHighway effort once upon a time. Since there's been virtually zero mention of it in any of the years and any of the master-plan revisions since, it's pretty clear they quickly found out how much of an engineering overreach the initial render was.

If this thing gets built, there'll be a simple low-profile overpass of Mass Ave. Station siting can be adjacent to one side or the other to minimize the track profile over the road-proper. Emphasis: overpass, not "viaduct". Per the T's own light rail design manual max grades on an incline are: 4.0% sustained, absolute 6.0% max for 2500 ft. length tangent track segments bookended by flat tangent sections. Per their BRT design manual for busways it's 5.6% in the open, and 0.5% on any switching points built to accommodate LRT conversion (i.e. Transitway turnouts only). On the RR design guide it's 1.5% max incline grades for new construction with *specific* FRA waivers only (such as: Wellington tunnel @ 3.5%, waivered for future Orange Line conversion; 3% for Mystic River Bridge on Eastern Route + Neponset River Bridge on Old Colony, waivered as fixed replacements for former draw spans over maritime-regulated water clearances).

You can do some awfully quick climbing from at-grade to 16 ft. state highway clearance over road with 4-6% grades. If the Mass Ave. LRT/BRT station were stacked on the less visually appealing power plant side of the crossing you could do the platform and get down under the overhang on trolley...then get down on the ground on the other side before even reaching the back side of the Metropolitan Storage Warehouse building. It's not visually impactful at all. RR...forget it. You don't have anywhere near the room between Mass Ave. and the plant overhang to do the climb at 1.5% grade on that side so it's 100% impossible right then and there. On the other side, even if you could you'd need 1067 ft. of incline room...putting you at midfield of the football stadium before reaching flat ground. Now thats visually impactful. It's no contest. Not only can Mass Ave. only be eliminated one way: by air with LRT/BRT, and never--on any mode--below because of the water-proofing blowouts...but any/all eliminations you do do would cost a fraction as LRT/BRT vs. what they would on RR.

MIT is not going to get bent out-of-shape about this when the benefits of building rapid transit with an aerial crossing elimination can be counted in $$$ gains to their endowment when any aesthetic objection either nets them crappier at-grade transit with worsened congestion or nothing at all...immediately countable by the Board in passed-up $$$ to their endowment growth. To them the bottom line impact is immediately FAR more compelling than the non-issue aesthetic nitpicks.

F-Line -- it's not the aesthetics of the Mass Ave overpass which is the key issue -- its what might be constructed -- reconstructed in that stretch of the Vassar St [i.e Metropolitan Warehouse up to the Power Plant] and the influence on the options for buildings in the immediate vicinity of the ramp

 

[F-Line to Dudley]

F-Line -- it's not the aesthetics of the Mass Ave overpass which is the key issue -- its what might be constructed -- reconstructed in that stretch of the Vassar St [i.e Metropolitan Warehouse up to the Power Plant] and the influence on the options for buildings in the immediate vicinity of the ramp

It can't influence building construction unless MIT demands more air rights overhangs...which the state is not obligated to give them no matter how hard they beg. It is a 60 ft. ROW with revokable service driveway easement on the north side. MIT can't touch anything at ground level in that 60 ft. swath; it's not theirs. Hence, each and every one of their building foundations on the Vassar corridor is outside the ROW ownership boundary (service driveway easement included).

The only reason they got the air rights easements for the power plant and Main St. is because Conrail was the line owner at the time, didn't give two shits but had to run the freights anyway, and saw short-term gain in the rent checks collected. They were too busy packaging themselves up for their eventual '99 merger-dismemberment by CSX and Norfolk Southern to care about considerations 5 years, let alone 20, down the line. Regardless of whether they even want any more air rights, abutting Mass Ave. is the last place they're going to seek them because of the exclusion zone around their nuke plant. All future action is going to be well behind the nuke + Metropolitan in Cambridgeport, where as per the last post the incline for an LRT/BRT Mass Ave. overpass isn't going to stretch far enough back to impact to begin with.

This isn't a real-world nitpick.

 

[stellarfun]

Some are having second thoughts on a section of the proposed design.

...But the most challenging aspect has been settling on a design for the crowded stretch of land between the Boston University campus and the Charles that’s known colloquially as “the throat." It’s where the eight-lane highway and four-lane Soldiers Field Road are joined by railroad tracks and a bicycle-and-pedestrian path alongside the river.

In Allston, impact of Mass. Pike reconstruction inspires second thoughts - The Boston Globe

Now that the construction hassles of the proposed Allston highway project are clear, some advocates are urging MassDOT to consider other alternatives.

www.bostonglobe.com

 

[shmessy]

Some are having second thoughts on a section of the proposed design.

In Allston, impact of Mass. Pike reconstruction inspires second thoughts - The Boston Globe

Now that the construction hassles of the proposed Allston highway project are clear, some advocates are urging MassDOT to consider other alternatives.

www.bostonglobe.com

Put that section underground. Everyone loves Deep Throat.

.

 

[Equilibria]

Some are having second thoughts on a section of the proposed design.

In Allston, impact of Mass. Pike reconstruction inspires second thoughts - The Boston Globe

Now that the construction hassles of the proposed Allston highway project are clear, some advocates are urging MassDOT to consider other alternatives.

www.bostonglobe.com

Of course people are having second thoughts about it - any of the options has tradeoffs and consequences. The question is whether we are going to let perfect be the enemy of good and whether our grandchildren will be asked by their kids why the Turnpike makes this stupid pointless turn through an open field in the middle of the city.

Will we dell them we dithered and dawdled and freaked out over hypothetical Commuter Rail delays?

 

[lexicon506]

How crazy would it be to temporarily shut down Storrow Dr. from Cambridge St. to Charlesgate for the duration of this project? It would cut costs, reduce the timeline, and avoid any environmental concerns from a temporary structure over the Charles. Traffic will be bad regardless, so why not make things just a little worse in exchange for money and time? And it may have the added benefit of getting people used to life without Storrow, making it's elimination or downsizing less of a pipedream..

 

[Equilibria]

How crazy would it be to temporarily shut down Storrow Dr. from Cambridge St. to Charlesgate for the duration of this project? It would cut costs, reduce the timeline, and avoid any environmental concerns from a temporary structure over the Charles. Traffic will be bad regardless, so why not make things just a little worse in exchange for money and time? And it may have the added benefit of getting people used to life without Storrow, making it's elimination or downsizing less of a pipedream..

Model it and find out. My guess is traffic would shift to the streets of the Back Bay (Mass Ave mostly) and to Memorial Drive through the River Street Bridge. I'm not sure either of those routes can take the additional load.

 

[jklo]

How crazy would it be to temporarily shut down Storrow Dr. from Cambridge St. to Charlesgate for the duration of this project? It would cut costs, reduce the timeline, and avoid any environmental concerns from a temporary structure over the Charles. Traffic will be bad regardless, so why not make things just a little worse in exchange for money and time? And it may have the added benefit of getting people used to life without Storrow, making it's elimination or downsizing less of a pipedream..

I think the project would get cancelled before they would do something like that.

 

[cden4]

The biggest problem I see is that MassDOT has insisted on keeping 12 lanes in the final configuration: 8 on I-90 and 4 on SFR. If they relaxed that requirement, they'd be able to easily fit everything at-grade. Given that the City's GoBoston 2030 plan looks to reduce the percentage of people driving alone to work by 50% by 2030, surely we can safely lose a few lanes. (And this project will still be under construction in 2030!)

 

[citylover94]

I would suggest the masspike lose a lane in each direction after the new exit they build. It goes down to three lanes at Prudential anyways so I don't think having the lane drop happen earlier would be that bad. Plus it would allow the pike to have breakdown lanes along its whole length instead of only in a few areas.

 

[whighlander]

The biggest problem I see is that MassDOT has insisted on keeping 12 lanes in the final configuration: 8 on I-90 and 4 on SFR. If they relaxed that requirement, they'd be able to easily fit everything at-grade. Given that the City's GoBoston 2030 plan looks to reduce the percentage of people driving alone to work by 50% by 2030, surely we can safely lose a few lanes. (And this project will still be under construction in 2030!)

cden -- not only is it obvious that you've never driven Storrow or the Pike at rush hour -- it's fairly obvious that you haven't even looked at the TV Traffic maps.

Under ideal circumstances the traffic flows slowly if acceptably. Add in any disruption and its essential to have a Plan B. One compromise would be keep the number of lanes but make one each way a breakdown lane [open for travel during rush hour].

The major improvement to the rebuilt Storrow and the Pike is in terms of auxillary structures in addition to the travel lanes. Both the Pike and Storrow were constructed in an era before universal breakdown lanes and similar auxiliaries to the travel lanes as well as inadequate arrangements for merging. I suspect that you could give up one full travel lane for breakdown and expanded merging. The footprint would not get any narrower than it is today -- but it might function more efficiently.

Ideally all the auxiliaries would be added to the existing four travel lanes and even more ideal -- more exits [W bound] and entrances [E bound] would be added where they were never included in the original layout.

 

[citylover94]

The federal gov't isn't allowing any new sections of breakdown lane travel and that is honestly worse imo than just not having a lane. Either way it would never be approved so that doesn't matter. I think taking it down by one lane in each direction would be okay and would in the long run encourage less people to drive into the city and instead take transit.

 

[Charlie_mta]

Taking the Pike taking down by one lane in each direction from Allston to Copley would create space and merge lanes for on-ramps to the EB Pike at Charlesgate. The 3 lane configuration would also allow shoulders along the entire route (except for the Throat)