B Line Improvements

Yeah gotta love the new MPO study. So basically what they're saying is that we can only convert an existing lane to HOV if there isn't too much traffic. Umm isn't that why you need HOV in the first place?
 
Why are we talking about HOV on a boulevard through an outer neighborhood? I thought this was a tongue-in-cheek conversation, but there's actually studies about it?
 
In addition to station consolidation signal priority on the B, what about some strategic grade separation via overpasses? You wouldn't need to El the whole thing or even all the way out to Packard's Corner. I could envision a single overpass over the BU Bridge intersection being very worthwhile, and maybe another one to get through Packard's Corner itself. You wouldn't need to elevate stations in either of these cases, so it keeps the cost way lower than an El.

I recognize that you need a specific graded incline on either end of the overpass but I think there should be room for this even if it means eliminating a surface stop or through cross-traffic at an intersection here or there...
 
Shepard said:
In addition to station consolidation signal priority on the B, what about some strategic grade separation via overpasses? You wouldn't need to El the whole thing or even all the way out to Packard's Corner. I could envision a single overpass over the BU Bridge intersection being very worthwhile, and maybe another one to get through Packard's Corner itself. You wouldn't need to elevate stations in either of these cases, so it keeps the cost way lower than an El.

I recognize that you need a specific graded incline on either end of the overpass but I think there should be room for this even if it means eliminating a surface stop or through cross-traffic at an intersection here or there...
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That's a lot of steel to erect. And it would be a tall incline since 16 ft. is the state highway clearance standard anywhere except where it's impossible. Probably going to cannibalize the Central platforms.

It might end up being easier and more useful to just exercise the Pike air rights around here and realign the intersection. If there's going to be a left-turn light cycle anyway, why can't it be at a turn lane-widened bridge intersection instead of spread over 2 conjoined intersections with insane lane weaving to get across. University Rd. is already too far a reach with obvious ped crossing issues to be worth the Storrow EB access. Why not a single intersection, eliminate the grade crossing at Mountfort/U Rd. altogether (because you can't left-turn to Comm. off U. Rd. anyway), and turn the Mountfort connector into a straightforward Carlton St. terminus. That's -1 light at one of the very worst lights on the B.

Hell...a slip ramp next to the SFA building onto Pike EB at the end of the viaduct would be worlds more useful than the existing Storrow EB entrance.
 
The whole bridge intersection is insane. Are you suggesting a simplification which allows left turns from the bridge into Comm Ave?
 
Matthew said:
The whole bridge intersection is insane. Are you suggesting a simplification which allows left turns from the bridge into Comm Ave?
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Yes. Take a BU air rights project over the Pike on the Mountfort block and use that as the excuse to fund it. Widen where the intersection overhangs the Pike so there's an appropriately long left turn lane on the NB side and run all Mountfort traffic here instead of diverting all at the Carlton intersection. Reshape the bridge side of the intersection *very slightly* for a left turn lane (not much work needed here). Use the existing excessive left lanes on 6-lane Comm Ave. as left turn lanes. When the lane drop project advances to Packards the roadway will be more naturally configured to allow that.

Rework the Carlton/Mountfort intersection into a simpler at-grade one like St. Mary's/Mountfort, ramp free. And fence off the B reservation here to zap the grade crossing and eliminate the light altogether. Turn the Mountfort/Comm. bridge into a straight Carlton St. extension serving the air rights BU buildings. Make it right-turn only onto Comm Ave. and right-turn only from Comm Ave. EB to traffic calm. The grade separation helps the B a ton and really de-gunks the weaving to the bridge. Anyone who wants to go to Storrow EB can U-turn downstream; not much is lost with University Rd. because existing Storrow traffic can only turn right on Comm., so the inconvenience of pulling a U for the other direction isn't that big (and arguably less dangerous than blasting across the intersection straight into jaywalking students).



Still not that pretty, but way better. And consolidated into a single intersection and single light cycle instead of that sprawling, all-mode FAIL. I never understood why they did it that way when they built the Pike. Especially severing Mountfort NB at Carlton and cramming all that volume through the weaving clusterfuck. NB volumes through the bridge intersection are nothing because of the severing. But Mountfort terrifyingly backs up across the entire intersection for drivers heading across the sea of weaving onto the bridge. Insanity.
 
You can improve this immediately in a simpler way.

Eastbound Comm Ave to the bridge: the second right only (onto Mountfort/Carlton) around and to the bridge.

Eastbound Comm Ave to Storrow: the first right only (onto Mountfort/Essex) and around to access University Rd - no left turn from there onto Storrow to access the bridge. .

Southbound on the bridge and on University Rd remains the same as today

Now, beautifully for the T, these two lights can go green for Comm Ave at the exact same time on the same cycle, and red for both crossings at the exact same time and cycle as well!
 
Need to get rid of those traffic islands preventing Mountfort from going straight onto Essex/BU Bridge, Shepard.

F-line, not sure about the Storrow EB-bound traffic in your design. They'd need to go down to Cummington Street to U-turn. What about making St Mary St 2-way? It's plenty wide as it is.

Also have to say that closing the Carlton Street crossing creates an awfully long stretch without a crossing. Especially since there's the GSU and the school right on one side there. I don't like the idea of blocking that off from pedestrians.
 
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Good point Matthew. And you make another good point about pedestrian crossings. This really irks me about the B. Why can the C be 100% open crossings but the B needs the fence for its whole stretch?
 
Shepard said:
Good point Matthew. And you make another good point about pedestrian crossings. This really irks me about the B. Why can the C be 100% open crossings but the B needs the fence for its whole stretch?
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THINK OF THE CHILDRENNNNNN!!!!!!

Really though, I think the restructured median with the greenspace on both sides helps a lot. Once you cross the two traffic lanes you have a safe haven in the median to wait for any trolleys before crossing the tracks and waiting to cross another two lanes. You currently don't have this ability on Comm Ave, so after dodging across traffic you have the potential to be plowed into by a trolley, since there is really nowhere to wait before crossing the tracks. The pastoral quality of the Beacon St reservation probably also helps, the dirt/grass and trees make people walk carefully across vs just plowing through. I imagine that once the Packards > Warren stretch is redone the fence will be removed.
 
Would a traffic circle work here? It would have to be just to the east of the current interchange otherwise you'd have to knock down 808 Comm Ave.

This is a terrible photoshop job but you get the idea.

24184122.jpg


Edit: That actually lines up surprisingly well.
 
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This would have to be more like a signalized New England style rotary rather than a true traffic circle, for many reasons including the B Line. At that point, what's the benefit other than a smaller footprint for the intersection?
 
Shepard said:
This would have to be more like a signalized New England style rotary rather than a true traffic circle, for many reasons including the B Line. At that point, what's the benefit other than a smaller footprint for the intersection?
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Assuming we want to keep to the circle idea, the couldn't B Line problem can be fixed with a short El instead? It can go under too, but that's probably too deep considering the Turnpike.
 
ant8904 said:
Assuming we want to keep to the circle idea, the couldn't B Line problem can be fixed with a short El instead? It can go under too, but that's probably too deep considering the Turnpike.
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Awkward to pull off. You need 16 feet of clearance for new overpass construction above a state-maintained road. And there needs to be about a trainset's worth of level track between the edges of a steep incline and the West and Central platform edges for safe braking distance. West's edge is only 400 ft. from maximum elevation; that stop is a goner for sure. Central's edge is 800 ft. from maximum elevation, and Comm Ave. starts climbing a hill between there and the bridge requiring a longer incline to compensate. Very tight fit if you figure there has to be a full 3-car consist's worth of braking distance off the incline to safely reach stops at the bottom of the incline (not an issue when it's a Blandford, St. Mary's, or Science Park at the top of an incline). If both stations get cannibalized there's now way too long a gap between stops, and not enough space overhead to build an El stop spanning the intersection. I really don't think that's going to work. They'll be wanting to replace it with something better almost immediately.


The Pike's not too bad to traverse in a subway if the tunnel deviates off-alignment at the Comm./University Rd. intersection and pulls into BU Academy's parking lot. Trace an arc from there (and your would-be station underneath the Academy lot) over to the park next to the SFA building and go back on-alignment around Armory St. The deeper descent/ascent is done through those grassy hillsides by the side of the Pike, under the edges of the BU Bridge retaining wall where supporting the roadbed above isn't an issue, and it cuts diagonally across the Pike when it's already on the incline up to the viaduct. Probably saves them from needing a tunnel boring machine by keeping the depth manageable, non-invasive to all above roadways except for the cut-and-cover across Comm Ave. WB (i.e. put up with metal plates on the road for 2 years), and not-awful costs since the underground utilities here were all consolidated when the Pike was built in '65, and there's nothing whatsoever under the Academy parking lot.

If there *has* to be grade separation here that's going to be a lot less fugly and operationally awkward for not much more money than an El. But I do think they can skirt the issue until there's actually a reason to subway it from Kenmore to an Urban Ring/Harvard branch/B split here. They just have to compact the intersection into something neat-and-tidy. It doesn't necessarily have to move traffic better, just be a single-point bottleneck instead of stretched like taffy over 2 blocks with the Weave of Terror at the Mountfort intersection.
 
It's less than 3/4 of a mile from the B portal to the BU Bridge. If any grade separation is justified wouldn't it just be easier (and cheaper) to just extend the tunnel a bit?

I will say that other then during the worst events Comm Ave is never that backed up. The biggest bottleneck is usually inbound at Warren Towers, where people ALWAYS double park, effectively reducing a major artery to one lane. Removing parking/standing spaces there was single handily the dumbest decision ever.
 
I recalled before traffic being back up. However, most of my most prominent recollection are the moments traffic gets back up and starts to block each other - Including the Green Line - and then they start honking to make the cars on the track scramble to move any way possible over.

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@F-Line - that's a good point. A El is just too steep with the hill. But you're also right that there's seem to be enough space for the Green Line to turn on to the current BU Academy Parking Lot and go under that street leading to the BU Bridge and then back up over the Turnpike but still avoid mingling with the circle. It can even go under the first set of Comm Ave and emerge in the center.

Something like this picture


(Paint skills)

The only thing to wonder is that the tunnel just ended 3/4 of a mile back. Arguably why not just continue it and just go up after the proposed circle (and it probably still have go to that route unless one really wants to dig under the Pike).

And if that is done, I wonder if some kind of space to the sides of the tunnel is possible. Unlike many other universities, there is no underground tunnels at BU connecting to building to building (not that its a need or priority). If such a tunnel is made, it might as well be a little wider and connected to the basements of CAS, GSU, and SMG or something like that (and also act like hidden basement entrances to stations.
 
signal priority seems like a way cheaper way to solve 90% of this problem.
 
choo said:
signal priority seems like a way cheaper way to solve 90% of this problem.
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It always comes back to signal priority, and forgive me for being ignorant, but what does that mean EXACTLY?

Would it be as simple as if the T is approaching an intersection, the T gets the right-of-way and gets the green while everyone else gets red? If so, why is this not already done? Is it really expensive, because it certainly doesn't seem like it should be.
 
bigeman312 said:
It always comes back to signal priority, and forgive me for being ignorant, but what does that mean EXACTLY?

Would it be as simple as if the T is approaching an intersection, the T gets the right-of-way and gets the green while everyone else gets red? If so, why is this not already done? Is it really expensive, because it certainly doesn't seem like it should be.
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The E to Brigham Circle and the entirety of the C are already wired up for it. All they have to do is install optical sensors pointed at the tracks that detect the shape of the oncoming trolley and the signal computers can force a prioritized red for the reservation. You'd be talking anywhere from $25,000-$100,000 in equipment to get it going. The T has simply resisted doing it despite pleas from City Hall and town of Brookline.

The B is another matter. Only the Blandford, Granby, Cummington, and St. Mary's signals have full computer controls. BU Bridge and all points beyond are old-time analog signals that are still run by mechanical switches (i.e. those switchboxes on the sides of the intersection still make an audible *click* when the signal phase changes). And Mountfort/University Rd., which did get a computerized signal, has a dependency on the BU Bridge signal phases and can't be prioritized until the Bridge gets re-signaled. Everything up to Warren St. is on-hold until MassHighway has funding to complete the next two segments of the road rebuild project. The most they can do in the short-term is wire up Blandford-St. Mary's, which doesn't buy much in the way of savings, and go fishing for money to wholesale-replace Summit Ave. to Lake St. where new signals wouldn't be dependent on unfunded changes to the road layout. There's still very little overall that they can do until the asphalt interests can fund the signal replacements. Although Summit-Lake St. would do modest good (moreso than Blandford-St. Mary's where greens run long and cross traffic is negligible).


The E past Fenwood also has analog signals, but those don't have much drag and they are supposed to be replaced at some point. Turning on the priority Brigham-Northeastern has more dramatic effect there.

I would argue C and E priority being pretty damn essential for keeping D's on-schedule all the way to Medford when GLX opens. They abandoned the plans to install crossovers on the Park inner inbound track for thru service, so anything at Kenmore or Copley that fouls a D is going to make schedule-keeping on the north end hard to pull off. If anything has to gum up the works, let it *only* be a GC-turning B instead of a pick-'em of B's, C's, or E's.
 
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