New Signal / Traffic Light System on the C Line

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Green Line Signal Priority

Postby F-line to Dudley via Park » Tue Jan 11, 2011 12:08 pm

http://www.boston.com/yourtown/news/bro ... Town_links

Looks like if the T's utterly indifferent to giving the Green Line signal priority at traffic lights the town of Brookline's going to take matters into its own hands with the C line. At least when it comes to giving trains priority over cars and pedestrian signals at Hawes St., Emory St., Englewood Ave., and Summit Ave. I would gather track signals would be the only expense since the town installed all-new centrally-controlled traffic signals from city line-to-city line along Beacon St. in the last 3 years, and paid for new T stop signals to go along with the replacements.

Main question would be whether the T would cooperate on installing track-based triggers for the lights or if the town's really going to take matters in its own hands and do the slightly less reliable (in bad/foggy weather) optical triggers mounted on the signal poles. Pesaturo's comment is typically not-reassuring: "...provided it happens at little or no cost to the MBTA."
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Re: Green Line Signal Priority

Postby RailBus63 » Tue Jan 11, 2011 1:02 pm

F-line to Dudley via Park wrote:Pesaturo's comment is typically not-reassuring: "...provided it happens at little or no cost to the MBTA."


The authority is in the midst of a massive financial crisis and has a $2.7 billion backlog of critical repair projects that are currently unfunded. It's entirely appropriate and responsible to put nice-to-have but otherwise non-urgent projects like this one on the back burner.
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Re: Green Line Signal Priority

Postby F-line to Dudley via Park » Tue Jan 11, 2011 4:19 pm

RailBus63 wrote:
F-line to Dudley via Park wrote:Pesaturo's comment is typically not-reassuring: "...provided it happens at little or no cost to the MBTA."


The authority is in the midst of a massive financial crisis and has a $2.7 billion backlog of critical repair projects that are currently unfunded. It's entirely appropriate and responsible to put nice-to-have but otherwise non-urgent projects like this one on the back burner.


Keeping the Green Line on-schedule is not-urgent and should be on the back burner? Wanna take a poll of B line riders and see if they agree with that stance?


The traffic lights and their control system are Brookline's, not the T's. Those surface trolley signals on the B, C, and E are "dumb"...simply wired to the intersection's regular road light cycle and controlled by those municipal electrical boxes on the sidewalk at each intersection. They're in no way centrally controlled by the T like all of the subway and D signals are, and the T doesn't even own or pay for them. The "smart" installations in Brookline and on the revamped portion of Huntington Ave. next to the reservation are just run-of-mill new municipal installations with computer instead of mechanical control, and ability to be centrally controlled by fiber or wireless signal. But they're still the city's lights, and the streets with trolley reservations are no different in their priority-signal infrastructure from all the other regular streets that got them. All of the new Beacon St. Brookline signals installed 3 years ago are remote-controllable, able to be triggered on-demand by emergency vehicles, and currently programmed to time variable lights cycles according to length of the car queues at an intersection. In fact, the trolleys are currently the ONLY vehicles not in some way measured by the sensors. But that's not because they aren't designed for it. Controlling light rail vehicles is no different for the signal controllers than controlling rubber-tire vehicles. It's plug-and-play, adding sensors to the trolley ROW, and treating it as if it were any prioritized traffic lane. There's no operational difference. The only added Green Line-specific infrastructure here would be the sensors mounted either on or above the tracks to trigger the lights. If it's an optical sensor, then it's exactly the same as the ones used for the roadway, just with a sensor pointed at the tracks from the trolley signal head instead of to a traffic lane from a roadway signal mount. If it's a track sensor, then it's just an off-the-shelf grade-crossing protection switch instead of one of those pavement-buried induction loops the cars use. Those aren't expensive, or all that state-of-the-art. Pretty much any surface-mounted triggers are designed cheaply because they have to be replaced fairly often due to weather and general wear-and-tear. On busy streets, for example, those induction loops get chewed up so quickly they only last a couple years.


How expensive is it to install those on 4 of Brookline's dozen or so signal-protected grade crossings? If that were any major capital investment then the cash-strapped DOT would put curbs on new installations of roadway traffic lights with their embedded road circuit or optical sensors, instead of happily erecting a new one every time some citizen persistently complains. It's the light assembly, mast arms, and control boxes that are the major expense; the sensors cost almost nothing. The pricey infrastructure is already in place on Beacon St., and Brookline purchased them on its own dime with the provision for easy trolley sensor hookup. I would buy the budgetary angle, but the T can't even keep its answers straight on why it doesn't want this. In 2007 (http://www.boston.com/news/local/articl ... de/?page=2) when Brookline installed the new lights and first approached them about wiring up the trolleys the excuse was that there was no demonstrated benefit to schedules or running time with signal priority. Which is bunk because that was a much-overhyped feature of the Silver Line Washington St. that they trumpeted to excess. They said they wanted Brookline to provide studies first before they'd even lift a finger to consider it. Brookline countered saying the T made it clear on first notice they weren't even interested in breaching the subject, and that biggest problem--preventing collection of whatever study metrics they wanted--was that they wouldn't even sit down and talk with them. It doesn't look like that's changed at all in the ensuing 3 years.

Maybe the ultimate reason does come down to budget, but how is anyone going to know that when the T cuts off all discussion at first mention? They can't really claim that as a viable reason if they're just going to turn down Brookline's persistent requests for a dialogue on this with a flat "La-la-la! I'm not listening!" refusal. It's stupid. I can't even picture what the agency's political angle would be to digging in so rigidly against this after lavishing the Silver Line with this technology with themselves paying part of the roadway expense...and making a loud ongoing push with official studies for doing exactly the same thing on the 39 corridor redesign while simultaneously refusing to consider hooking the E reservation up to the new "smart" lights on Huntington equally set up as plug-and-play for trolley sensors.
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Re: Green Line Signal Priority

Postby boblothrope » Tue Jan 11, 2011 6:04 pm

F-line to Dudley via Park wrote:In 2007 (http://www.boston.com/news/local/articl ... de/?page=2) when Brookline installed the new lights and first approached them about wiring up the trolleys the excuse was that there was no demonstrated benefit to schedules or running time with signal priority. Which is bunk because that was a much-overhyped feature of the Silver Line Washington St. that they trumpeted to excess. They said they wanted Brookline to provide studies first before they'd even lift a finger to consider it. Brookline countered saying the T made it clear on first notice they weren't even interested in breaching the subject, and that biggest problem--preventing collection of whatever study metrics they wanted--was that they wouldn't even sit down and talk with them.


Well, *someone* should have made it their business to get to the bottom of the miscommunication/stonewalling. How about the Secretary of Transportation? Or the T's General Manager, who seems to be reasonably approachable and interested in getting problems solved?

I'd be interested in volunteering to do the study the T supposedly asked for. It could be as easy as standing around at a few intersections at rush hour, timing how long trolleys sit at red lights, and counting the number of side street vehicles and pedestrians that cross during those lights.

When I first heard about optical traffic detectors, I was skeptical about their reliability in various conditions. But at the (very few) intersections around here that have them, I've been thoroughly impressed. They sense vehicles perfectly well, and allow the controllers to do things like shortening the major street's green if there are no cars coming for a moderate distance.

With optical detectors, Brookline wouldn't even *need* the T's cooperation. They could just install them pointing at the tracks.
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Re: Green Line Signal Priority

Postby F-line to Dudley via Park » Tue Jan 11, 2011 6:44 pm

boblothrope wrote:With optical detectors, Brookline wouldn't even *need* the T's cooperation. They could just install them pointing at the tracks.


I think that is the nuclear option here since it's their signal installations, and going public about it is a little saber-rattling after 3 years of being stonewalled to try to draw the T to the table. It would not go over well for MBTA-Brookline relations in the long term if they went rogue and installed sensors unilaterally, so they're correctly reluctant to go that route. But I suppose if the wall of cognitive dissonance from the T is impenetrable, they'll ultimately have to do what they have to do. Beacon St.'s the primary artery for the whole town, and the C the primary generator of pedestrians (and commercial revenue) on the whole corridor. If traffic flow's not functioning well enough and citizens are complaining that the line moves too needlessly slow through signaled intersections, it's in their best interests to explore the most feasible solutions. This is the most feasible solution because the infrastructure's already in-place. Only a matter of what price--figurative and literal--for the T's cooperation or lackthereof.
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Re: Green Line Signal Priority

Postby jamesinclair » Tue Jan 11, 2011 7:42 pm

RailBus63 wrote:
F-line to Dudley via Park wrote:Pesaturo's comment is typically not-reassuring: "...provided it happens at little or no cost to the MBTA."


The authority is in the midst of a massive financial crisis and has a $2.7 billion backlog of critical repair projects that are currently unfunded. It's entirely appropriate and responsible to put nice-to-have but otherwise non-urgent projects like this one on the back burner.


Im so glad you're not running thing.

Let's ignore the whole customer service deal about getting people to work faster.

Less waiting time = shorter run time.

Shorter run time, over the course of the day = more runs with same staffing (or less staffing with the same amount of runs)


Its also EXTREMELY cheap to do.
You either install a camera, which detects the MASSVIVE vehicle,
or
You install an induction loop, that detects the metal (like those under the pavement at every intersection)
or
You install a 5 dollar ir thingy, like those shopkeepers use to make a beeping noise when a customer opens the door and interrupts the beam of light.

Connect whatever sensor you want to the existing installation...

AND DONE.


Here are what the induction sensors for cars (and bikes) look like.
http://maps.google.com/maps?f=q&source= ... 4,,1,21.83
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Re: Green Line Signal Priority

Postby ThinkNarrow » Tue Jan 11, 2011 10:08 pm

jamesinclair wrote:Here are what the induction sensors for cars (and bikes) look like.
http://maps.google.com/maps?f=q&source= ... 4,,1,21.83

...and here's a nice website about video detection systems:

http://www.modot.gov/stlouis/links/signalcameras.htm

-John
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Re: Green Line Signal Priority

Postby RailBus63 » Thu Jan 13, 2011 10:06 am

F-line to Dudley via Park wrote:
RailBus63 wrote:
F-line to Dudley via Park wrote:Pesaturo's comment is typically not-reassuring: "...provided it happens at little or no cost to the MBTA."


The authority is in the midst of a massive financial crisis and has a $2.7 billion backlog of critical repair projects that are currently unfunded. It's entirely appropriate and responsible to put nice-to-have but otherwise non-urgent projects like this one on the back burner.


Keeping the Green Line on-schedule is not-urgent and should be on the back burner? Wanna take a poll of B line riders and see if they agree with that stance?


Nice straw man argument. Nowhere did I state that keeping the Green Line on schedule is unimportant. I’m all for improving Green Line on-time performance, but any proposals that cost money need to be looked at carefully right now. If a project can pay for itself, then great. In this case, since the service improvement would be unlikely to significantly increase ridership on the C line, payback would probably mean using faster running times to remove a train from the line and maintaining the same headway.

Also, bringing up the Silver Line isn’t germane to this argument, since the signal-priority work on that line was paid for by Federal dollars (I believe the same is also true of the planned Route 39 improvements).

jamesinclair wrote:
Im so glad you're not running thing.


Why? Because I see a transit agency that is essentially broke, with little to no hope of a bailout from a state that is also broke? Heck, if I was running the show, I would go a lot further than this to cut off unnecessary expenditures until the critical upkeep backlog is addressed.

I honestly don’t think some folks here have a realistic grasp of the MBTA’s financial dilemma. As someone who lived through the dark ages of the late 1970’s and early 1980’s, I have no desire to see a repeat of what happened then – widespread missed trips due to lack of available equipment, cars literally held together with duct tape, massive service cutbacks and threatened weekend shutdowns, etc. It would be far better to take steps now to address this, and delay some worthwhile improvemnts for a little while, than to wait until the crisis gets worse.
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Re: Green Line Signal Priority

Postby boblothrope » Thu Jan 13, 2011 12:57 pm

RailBus63 wrote:Also, bringing up the Silver Line isn’t germane to this argument, since the signal-priority work on that line was paid for by Federal dollars


Does the Silver Line's signal priority actually exist?

http://www.nbrti.org/media/evaluations/ ... report.pdf , a consultant's report to the Federal government, says it wasn't yet working in 2005, 3 years after the line opened.

It also says it was only planned at 4 intersections, and would only work when a bus was running late, as determined by the central computer's analysis of the bus's GPS data.
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Re: New Signal / Traffic Light System on the C Line

Postby Disney Guy » Thu Jan 13, 2011 1:49 pm

Various kinds of traffic signal priority can be developed for the C line and requiring no modifications to the trains and requiring no action by the motormen. But dealing with passenger stop is tricky. Either the priority has to be omitted from intersections that the train stops just in front of, or the motorman has to request priority either using either a push button or by advancing the train slightly. (The train would get a non-prioritized green light just by sitting there.)

I would think that Coolidge Corner and also locations with three way signals or other long cycle signals should have transit priority. One easy system lets trains go either before or after the left turn phase depending on when the train gets there while straight through autos go only in the normal sequence, before or after the left turn phase but not both.
(To the theater stage manager) Quit twiddling the knob and flickering the lights while the audience is entering and being seated. (To the subway motorman) Quit twiddling the knob and dinging the doors while passengers are getting off and others are waiting to board.
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Re: New Signal / Traffic Light System on the C Line

Postby diburning » Thu Jan 13, 2011 2:16 pm

Why not program a delay into the signal? For example, a 20-30 second delay at Coolidge Corner for the station stop, then it would give the train the signal to go. It would only cut 20-30 seconds off of express trains (with the current system it probably cuts more).

If they can program delayed greens for vehicular traffic, then the GL signal should be no different.
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Re: Green Line Signal Priority

Postby F-line to Dudley via Park » Thu Jan 13, 2011 3:00 pm

RailBus63 wrote:Nice straw man argument. Nowhere did I state that keeping the Green Line on schedule is unimportant. I’m all for improving Green Line on-time performance, but any proposals that cost money need to be looked at carefully right now. If a project can pay for itself, then great. In this case, since the service improvement would be unlikely to significantly increase ridership on the C line, payback would probably mean using faster running times to remove a train from the line and maintaining the same headway.

Also, bringing up the Silver Line isn’t germane to this argument, since the signal-priority work on that line was paid for by Federal dollars (I believe the same is also true of the planned Route 39 improvements).


RailBus63 wrote:I honestly don’t think some folks here have a realistic grasp of the MBTA’s financial dilemma. As someone who lived through the dark ages of the late 1970’s and early 1980’s, I have no desire to see a repeat of what happened then – widespread missed trips due to lack of available equipment, cars literally held together with duct tape, massive service cutbacks and threatened weekend shutdowns, etc. It would be far better to take steps now to address this, and delay some worthwhile improvemnts for a little while, than to wait until the crisis gets worse.


Are you buying the T's stawman argument that signal priority has no proven benefit? Or that it only helps buses, not trolleys? My B line comment was not snark. So many runs blow their schedules on the surface branches because of mixed-traffic congestion that the T cannot keep the line's throughput balanced during rush hour. You have bunching, followed by gaps, trains needing to abort runs with short-turns, trains needing to run express to catch up through stops, and frequent schedule-correction layovers at stops. All because trains can't traverse all those traffic lights within their allotted schedule slots, and because it's impossible to predict on a set schedule where the backups will be. It's "widespread missed trips" all the same. Like with deferred maintenance it degrades service quality, causes complaints (even on the C, which isn't as bad at this as the B), and makes the public lose confidence in the transit authority's ability to function. And, most importantly, it costs them revenue. Every aborted run, every train that has to express, every time the operators have to wave the last few people in a huge boarding queue on without paying (or with an IOU that isn't honored)...it's lost revenue. Just like every passenger who gives up when they don't see any train for 20 minutes, sees 3 or 4 in a row pass the other direction, and/or can't get on the one that finally does come because it's too full...is lost revenue.

If the state's in such dire shape that four grade crossings' worth of transponders at signal-priority installations already bought and paid-for by the munipality is too much a cost to bear...then they aren't going to have money to do any basic maintenance anyway. Or drop $2B down the drain on the South Coast. Or build the Somerville extensions. Or keep buying new bus fleets on the aggressive schedule they're doing. Or build fancy, expensive, climate-inappropriate glass enclosures on renovated stations. Or make a bunch of consultants rich shoveling study money at study projects that never seem to advance anywhere except making consultants money. Or keep the lights on. Or pay a General Manager a General Manager's salary.

It's a false equivalency that every dollar is equally bad when there's a budget deficit. It's not. You made the point yourself that maintenance is too important to skimp on because of how it degrades service and public confidence. Well...schedule-keeping is a cost that keeps service from degrading. And other than having operational cars I can't think of anything more important to maintaining schedules than having working traffic control. Traffic control on the surface branches is failing. It costs a lot more to build all-new infrastructure than enhance existing infrastructure. All of the C and all of the reservation-running E have city pre-installed traffic control infrastructure. A very conservative start at 4 intersections on the C would require at most a couple hundred grand's worth of transponders and wiring hook-up to the existing signals (if that...road transponders are mass-produced to be borderline-disposable, so they've got to be pretty cheap). Not only is that not hard, it's high bang-for-buck if the cumulative effect keeps more runs on-schedule and more fare revenue being pocketed. They don't have an excuse for crying poverty at this micro-level when they're content to throw all kinds of money at other projects--worse, vaporware projects--that do nothing to protect the long-term reliability of baseline services.
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Re: New Signal / Traffic Light System on the C Line

Postby F-line to Dudley via Park » Thu Jan 13, 2011 3:18 pm

Disney Guy wrote:Various kinds of traffic signal priority can be developed for the C line and requiring no modifications to the trains and requiring no action by the motormen. But dealing with passenger stop is tricky. Either the priority has to be omitted from intersections that the train stops just in front of, or the motorman has to request priority either using either a push button or by advancing the train slightly. (The train would get a non-prioritized green light just by sitting there.)

I would think that Coolidge Corner and also locations with three way signals or other long cycle signals should have transit priority. One easy system lets trains go either before or after the left turn phase depending on when the train gets there while straight through autos go only in the normal sequence, before or after the left turn phase but not both.


The advancing-train-slightly method is the most oft-used method because that's operationally very similar to how trolleys and trolleybuses turn at a junction (either powering through for one direction or cruising through for the other). Apples/oranges on the technology side, but consistent with how operators have been trained for over a century to use positioning through switches. In that case when the train closes the doors at a platform it would pull up to a stop line at the crossing with a track switch that auto-triggers the light.

If an optical sensor, they would probably be able to self-detect when the door shuts by the train's front marker lights changing from blinking red to green.
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Re: New Signal / Traffic Light System on the C Line

Postby RailBus63 » Thu Jan 13, 2011 3:21 pm

I'll amend my earlier position and agree that projects of this type should be looked at on a cost-benefit basis, but I’d have to see numbers that show that there was a definite payback for the investment (even if it is only a few hundred grand). And I’ll definitely agree with you that the MBTA too often wastes money on studies and other garbage that add little value, which is why I am advocating that all expenditures get a closer look.
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Re: Green Line Signal Priority

Postby CRail » Thu Jan 13, 2011 8:59 pm

F-line to Dudley via Park wrote:If the state's in such dire shape that four grade crossings' worth of transponders at signal-priority installations already bought and paid-for by the munipality is too much a cost to bear...then they aren't going to have money to do any basic maintenance anyway. Or drop $2B down the drain on the South Coast. Or build the Somerville extensions. Or keep buying new bus fleets on the aggressive schedule they're doing. Or build fancy, expensive, climate-inappropriate glass enclosures on renovated stations. Or make a bunch of consultants rich shoveling study money at study projects that never seem to advance anywhere except making consultants money. Or keep the lights on. Or pay a General Manager a General Manager's salary.

Right on!!!

This is why I threw such a fit over the OPTO thing. They have no interest in trying to save money or cut the deficit, they only cry that to get out of stuff. It's a thing of convenience, really.

Station portals throughout the system have sensors installed which detect objects passing through them to set off an alarm in the OCC. They're programmed to know what the shape of a train is, and the shape of small rodents so that they don't go off for ether of the two. But if something the size and shape of a person passes through, it sends an alert to the appropriate dispatcher. Please tell me what study (and at what cost) went into proving this non-sense beneficial to service, and then the decision to purchase, install, and maintain this system. Really, THAT is worth more to the T than a few lousy detectors to increase the quality of service? If your next door neighbor can't afford a box of your daughter's girl scout cookies, but parks his brand new Mercedes SUV in his 2 car garage every night, it's not really the cost of the cookies keeping him from buying.
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