When buses are clumped like that, the leading bus shall not stop at the next bus stops until the distance between them becomes sufficient.
But what if I (or all passangers) want to get off at the next stop?
Why Do Buses Bunch?
121–130 of 153 posts
Re: Why Do Buses Bunch?
#122Earlier quoted context omitted.
TL;DR - Teleportation will solve public transit problems.
Except for all those poor people that are still in the bus when it teleports :P
then again, if you have teleportation, you probably do not need the bus in the first place (did I just explain the joke?).
Re: Why Do Buses Bunch?
#123I enjoyed the callout to this when I was reading Google's Percolator paper a few years ago: > The random-scanning approach requires one additional tweak: when it was first deployed we noticed that scanning threads would tend to clump together in a few regions of the table, effectively reducing the parallelism of the scan. This phenomenon is commonly seen in public transportation systems where it is known as “platooni…
> To further the transportation analogy, the buses (scanner threads) in our city avoid clumping by teleporting themselves to a random stop (location in the table) if they get too close to the bus in front of them. Subway trains do this "to regulate service" iirc is the term used on the London Underground. Takt time［1］and Drum Buffer Rope［2］both related concepts of regulating flow through a process/system. ［1］ https:/…
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Re: Why Do Buses Bunch?
#124Earlier quoted context omitted.
This is possible with public transportation too. Trains run express and skip stops all the time. I think that would be too much hassle with buses but it's possible.
I have seen full or near-full buses skip scheduled stops to alleviate this. Although from a waiting passenger's POV, having an already delayed bus that has space left zoom past you without stopping is pretty infuriating...!
Buses in my town back in the 2000's would just turn off their signs when they were doing this.
Re: Why Do Buses Bunch?
#125When buses are clumped like that, the leading bus shall not stop at the next bus stops until the distance between them becomes sufficient.
But what if I (or all passangers) want to get off at the next stop?
Then you could get out at the current stop and let the next bus take you to the next one. I've seen this in New York where trains become 'express trains' Im shure other cities do this too.
Re: Why Do Buses Bunch?
#126Earlier quoted context omitted.
London subway trains teleport themselves?
No they don't. When you hear "to regulate the service" what they actually do in my experience is delay trains to try and introduce a more even service. So if you have trains that are: |--|--|--|------------|--| Then they will delay some of the trains such that it becomes: ---|--|--|--|--------|----| i.e. reduce the speed of the lead trains to try and reduce bunching. So generally if you hear "to regulate the service"…
Lothian buses regulate as well, but only to maintain published timetables (if a bus is running fast, it will sit at a stop until it's back on schedule)
The usual clumping is multiple buses on separate routes arriving at one, since they enforce strict stacking (can disembark in the approach to the stop but can only embark passengers at the stop sign)
Re: Why Do Buses Bunch?
#127Earlier quoted context omitted.
https://en.wikipedia.org/wiki/IBus_(London) is part of it. Also https://www.intelligenttransport.com/transport-articles/688/... http://www.eltis.org/sites/default/files/case-studies/docume... It's not actually clear if the de-bunching is algorithms or humans: >Headway information, the time gap between consecutive buses, will be available to a bus driver at all times on a screen so that they can make decisions such as…
Either way that's a great use of technology. AVLs and annunciators aren't exactly new technology (both exist with SF's Muni, for instance), but the MTA has definitely not used this data to avoid bunching — even in the subway.
Yeah. Sometimes when you get a bus to X it'll stop saying 'this bus terminates here' after about one stop, well short of X. When I asked the driver WTF he said it's the computer system and if they have too many empty busses going down one route they'll reallocate. There's nearly always another bus a couple of minutes behind to take you to X.
I was thinking someone could build quite a lot of the functionality into a free phone app if the drivers were willing to use it.
Re: Why Do Buses Bunch?
#128Earlier quoted context omitted.
London subway trains teleport themselves?
No they don't. When you hear "to regulate the service" what they actually do in my experience is delay trains to try and introduce a more even service. So if you have trains that are: |--|--|--|------------|--| Then they will delay some of the trains such that it becomes: ---|--|--|--|--------|----| i.e. reduce the speed of the lead trains to try and reduce bunching. So generally if you hear "to regulate the service"…
There are express services but only on the metropolitan line (which uses above ground tracks shared with non-TFL trains).
Re: Why Do Buses Bunch?
#129Earlier quoted context omitted.
I'm not aware of any metro system in the world that has scheduled headways of under a minute. The Moscow Metro was tops for a long time with 95-second headways on some lines at peak (without full automation, mind you), but Paris Metro Line 1 was recently fully automated and can go as low as 85 seconds. Singapore currently has 120 second headways on its busiest line (East/West, which is not automated) and is working o…
Victoria line on the London underground does 100 seconds, with plans for the Northern Line to reach that too FWIW. Doesn't really help much though. Sometimes you still have to wait 2 or 3 (or more!) trains before you can get to the front of the platform edge so that you can actually get on though!
TPH on Victoria line is now limited by platform constraints I think, you literally can't move passengers through stations like Stockwell any faster because of the size of the passageways.
Re: Why Do Buses Bunch?
#130Earlier quoted context omitted.
If nobody signals to get off, buses sometimes will skip if they're bunched. I've seen it in at least three cities before. I have no idea if it's policy or if the drivers on those routes juts took matters into their own hands. I see bunched buses on the stop right outside my work basically every day. Sometimes four from one route and another three from another parallel route all within a ~5 minute span. Mercer in Seat…
Not stopping when nobody signals is the point of the signal right:).
edit: Well, I guess the bus could then ignore passengers on the tarmac wanting to get on.
That's another thing.