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Why Do Buses Bunch?

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Re: Why Do Buses Bunch?

#141

Post by theluketaylor »

mcv wrote: post #132
joncrocks wrote: post #112

Earlier quoted context omitted.

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"…

I've often felt that maybe the front bus should skip a few stops, but unfortunately, the fuller a bus is, the bigger the chance that someone has to get out at every stop, and that means people are going to get in at every stop too. Maybe the empty rear bus should overtake the front bus, but that's not always possible. Teleporting to a random stop would be really annoying for people who had to get out at the next stop…

When I was growing up in Calgary when buses bunched the lead bus would linger at a stop specifically so the other buses could pass and even out the ridership.

The transit system even employed this on purpose at busy times since Calgary is such a suburban city. It's fairly rare in the morning for people to need to get off until a major intersection or light rail station. Buses were sent in pairs (sometimes three) to run the same route, leapfrogging each other at every stop. If someone did ask for a stop the driver would radio ahead and the lead bus would skip the stop. Taking the bus route at a leapfrog time really did cut the journey time down significantly. The technique doesn't work quite as well coming home since you can't predict when people will need to get off.

Re: Why Do Buses Bunch?

#142

Post by dalore »

userbinator wrote: post #96
kuldeep_kap wrote: post #78

Earlier quoted context omitted.

You are forgetting people who would want to get off that stop, so this is may not be an option.

The bus in front will have more people, and more likely to stop to let people off (and on). Meanwhile, the one following behind will be emptier, and thus less likely to need to stop, meaning it can easily pass the one in front (while that one is at a stop for entering/exiting passengers) and then itself take on more passengers at the stops ahead --- which then gradually slows it down too, but at the same time the one…

Wouldn't that mean when the bus overtakes it's now taking more passengers and therefore slowing down. The bus it just overtook (which would have quite a few passengers) is now speeding up (but also having to drop off passengers, possibly even stopping at the same stops the previous bus just stopped at.

So it just adds more bunching, doesn't fix anything.

If the bus that overtakes doesn't stop at the next stop but overtakes several stops (or until a passenger needs to get off but should be rare as emptier then the bus it overtook). And then start from there.

Someone mentioned this solution but called it random teleport.

Re: Why Do Buses Bunch?

#143

Post by lenticular »

fwip wrote: post #89
lenticular wrote: post #71

Earlier quoted context omitted.

When that app (OneBusAway) first came out, it was extremely accurate. It completely went to crap when Metro took over maintenance.

It's very accurate now. I don't know when your experience with it was. It pulls from the same source that Google Maps currently does, so feel free to use whichever you prefer.

I last used it about 4 or so years ago, so of course things may have changed. It was appallingly bad though, to the point where it was no more accurate than posted schedules on the routes I rode. I just quit using it because it was so thoroughly useless. The sad thing is that it previously had worked extremely well. Glad to hear they've fixed the issues.

Re: Why Do Buses Bunch?

#145

Post by Izkata »

btbuildem wrote: post #101
jpatokal wrote: post #92

Earlier quoted context omitted.

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...!

Perhaps the bus that caught up to the full bus should pass it, and relieve the next stop - presumably there are extra passengers waiting at that one too, since the bus is late. This way the bus that caught up will now risk slowing down (dealing with fuller stops), but the original full bus that was slow is likely to not speed up that much, having an above-average number of potentially disembarking passengers.

This is what CTA buses in Chicago do, though the full bus doesn't slow down. They end up leapfrogging down the route.

Re: Why Do Buses Bunch?

#146

Post by cozzyd »

PavlikPaja wrote: post #135

There are several ways to avoid this. 1. The buses have predetermined stop times, signalled by a beep. You don't get on in time, you don't get on at all. Makes the delays predictable, regardless of the number of passangers. 2. Lines go from A to B and back, rather than in circles, so the delays cannot accumulate. These are known and widely used. There is no reason why this should happen.

#1 is extremely non-ADA compliant but might work in countries other than the US.

Re: Why Do Buses Bunch?

#147

Post by zaphod12 »

mcv wrote: post #132
joncrocks wrote: post #112

Earlier quoted context omitted.

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"…

I've often felt that maybe the front bus should skip a few stops, but unfortunately, the fuller a bus is, the bigger the chance that someone has to get out at every stop, and that means people are going to get in at every stop too. Maybe the empty rear bus should overtake the front bus, but that's not always possible. Teleporting to a random stop would be really annoying for people who had to get out at the next stop…

This happens with the subway in NYC all of the time - a very crowded train will announce that it's running express to X stop...a thousand people get off and onto the next one to continue on.

It's quite annoying when it's you that has to get off and wait, again, haha, but appears to be the right move for the system

Re: Why Do Buses Bunch?

#148

Post by munk-a »

cimmanom wrote: post #55
pushpop wrote: post #44

Earlier quoted context omitted.

Clearly not. You’re not going to hold people captive on the bus just to make up a few minutes. However that doesn’t mean the bus drive has to accept new passengers when someone does get off (it’s not common that happens but I have seen that happen before and it’s highly infuriating for those waiting for the bus. Which is likely why it’s not common)

My experience on crowded buses is that typically every stop gets rung for anyway, so skipping isn’t an option. Of course, if it were possible to open only the back doors and let people off but not on, that might help, at the expense of leaving the people waiting to get on enraged. But then you also have the problem that on a crowded bus it can be really tough to squeeze past the rest of the passengers to get off, whi…

Vancouver buses have this ability! And they will often specifically refuse to let new people on the bus if they are at or near capacity.

It noticeably speeds up things.

Re: Why Do Buses Bunch?

#149

Post by munk-a »

zifnab06 wrote: post #95
munk-a wrote: post #20

Interesting, that simulator shows buses that are often full. I think that's a rather rare case and know of a pretty graspable reason why lower fill buses clump up quite a bit. Assume that a stop produces a customer every minute or so, if a bus is five minutes late to the stop (lets say due to traffic) it will take a bit longer to load customers than normal adding slight amounts to its delay over time - concurrently,…

In Seattle, where we mostly lack any sort of useable rail, it's entirely normal to have full busses, especially at rush hour. Bunching does happen and I love it because it makes my commute home quiet.

Yea uh... can you guys fix that? Metro is a godsend and Seattle suffers greatly from the lack of it - it's super annoying to try and bus to interesting parts of the city because the traffic in those areas tends to be terrible.

(I'm in vancouver now but for a while I was regularly flying in from the US and I'd usually fly to seattle and then catch the train/amtrack bus up the last leg due to the stupidly large price difference)

Re: Why Do Buses Bunch?

#150

Post by o_nate »

tim333 wrote: post #10
caymanjim wrote: post #7

This is very common in Manhattan. Whenever I saw a full bus, I'd skip it and wait for the next one, because it was almost certainly going to come along within 5 minutes and be pleasantly uncrowded. On a busy route, it's the sensible choice. On longer-distance commuter routes, where the scheduled times are 30-60 minutes apart, I wouldn't usually take a chance on waiting for the next one, but I even did that on occasio…

It's mostly been fixed in London. They used to be famous for no busses for 20 mins then 3 at once but they are now controlled by a central computer system which knows all the positions via gps and cell data.

It probably also helps that they allow people to load at both the front and back of the bus, and they check tickets while the bus is in motion. Buses in the US generally have people load one at a time through the front door and everyone's ticket has to be checked or (even worse) they have to feed dollar bills through the machine. This greatly increases per-person load times, and exacerbates the bunching effect.
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