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Why Do Buses Bunch?

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Re: Why Do Buses Bunch?

#41

Post by foota »

umvi wrote: post #30
adrianmonk wrote: post #26

Would it help to have the trailing bus pass the leading bus when they bunch up? My reasoning: (1) As the article said, full buses move slower because more passengers means more boarding/unboarding time at stops. (2) The lead bus is the fuller, slower one. Slower bus in front means buses get closer together. (3) If one bus passes the other, then you have the faster bus in front and the slower one behind. They should t…

You could probably have a computer calculate which stop the trailing bus should jump ahead to. Then you have the trailing bus switch to "out of service" mode (so it doesn't enrage people when it passes a bunch of stops) and skip ahead 4 or 5 stops or whatever the computer decides is optimal.

This may not work as well as you'd like if passengers need to get off frequently.

Re: Why Do Buses Bunch?

#42

Post by eMSF »

umvi wrote: post #30
adrianmonk wrote: post #26

Would it help to have the trailing bus pass the leading bus when they bunch up? My reasoning: (1) As the article said, full buses move slower because more passengers means more boarding/unboarding time at stops. (2) The lead bus is the fuller, slower one. Slower bus in front means buses get closer together. (3) If one bus passes the other, then you have the faster bus in front and the slower one behind. They should t…

You could probably have a computer calculate which stop the trailing bus should jump ahead to. Then you have the trailing bus switch to "out of service" mode (so it doesn't enrage people when it passes a bunch of stops) and skip ahead 4 or 5 stops or whatever the computer decides is optimal.

Both buses probably need to drop off passengers, though (who would likely be a lot more enraged than people who don't get picked up by the first bus if they didn't get out where they wanted).

Anyway, I think the leading bus skips stops when possible, at least here. I don't think people mind that too much, because for all they know, the bus might simply be too full, although that certainly only happens on exceptional circumstances if ever around here.

Re: Why Do Buses Bunch?

#43

Post by grawprog »

adrianmonk wrote: post #26

Would it help to have the trailing bus pass the leading bus when they bunch up? My reasoning: (1) As the article said, full buses move slower because more passengers means more boarding/unboarding time at stops. (2) The lead bus is the fuller, slower one. Slower bus in front means buses get closer together. (3) If one bus passes the other, then you have the faster bus in front and the slower one behind. They should t…

When busses get bunched here, the lead bus just tends to skip stops and leave them for the trailing bus. This doesn't really seem to help much. They usually both stay pretty close together and, as a passenger, you end up standing there confused as to whether the bus just left you or not if you can't see the one behind.

Re: Why Do Buses Bunch?

#44

Post by pushpop »

cimmanom wrote: post #36
munk-a wrote: post #23

Earlier quoted context omitted.

Out here (vancouver) operators are allowed to skip stops when full, so they are able to recover from this state gracefully. Depending on the frequency of the bus route I'd prefer adherence to a schedule vs. efforts to minimize bunching. With frequent buses I think the schedule ends up being irrelevant - but if the hourly bus I occasionally take pulls in fifteen minutes early or late then I will be pissed, especially…

Are they allowed to also skip stops where people want to get off?

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)

Re: Why Do Buses Bunch?

#45

Post by seaish »

adrianmonk wrote: post #26

Would it help to have the trailing bus pass the leading bus when they bunch up? My reasoning: (1) As the article said, full buses move slower because more passengers means more boarding/unboarding time at stops. (2) The lead bus is the fuller, slower one. Slower bus in front means buses get closer together. (3) If one bus passes the other, then you have the faster bus in front and the slower one behind. They should t…

This would help with not wasting the trailing bus's extra speed, but I think the buses being that close together is already considered failure. And in the real world, there would be many more stops on a circuit. Any advantage the faster bus has will be reset in 1 or 2 stops, and on a route with 10-20 stops, the extra space between them is negligible.

Re: Why Do Buses Bunch?

#46

Post by Taniwha »

adrianmonk wrote: post #26

Would it help to have the trailing bus pass the leading bus when they bunch up? My reasoning: (1) As the article said, full buses move slower because more passengers means more boarding/unboarding time at stops. (2) The lead bus is the fuller, slower one. Slower bus in front means buses get closer together. (3) If one bus passes the other, then you have the faster bus in front and the slower one behind. They should t…

Of course trolley buses (or streetcars/trams) can't do this

Re: Why Do Buses Bunch?

#47

Post by xyzzyz »

dmoy wrote: post #8
telesilla wrote: post #6

Thanks for letting me relive nightmare memories of Grand Ave in Chicago! I always wondered, why couldn't the bus drivers be in communication and have the front bus just skip a couple of stops (where people are waiting) when they bunched, which was often even 3 buses!

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…

Mercer traffic is pretty good outside of the times of day when it’s closed and used for parking.

Re: Why Do Buses Bunch?

#48

Post by iblaine »

This happens daily on the Muni 30X in San Francisco. What this algorithm needs is a comfort level such that a persons decision to get on a bus is a function of their expected comfort level and expected arrival time.

Re: Why Do Buses Bunch?

#49

Post by nicoburns »

eMSF wrote: post #42
umvi wrote: post #30

Earlier quoted context omitted.

You could probably have a computer calculate which stop the trailing bus should jump ahead to. Then you have the trailing bus switch to "out of service" mode (so it doesn't enrage people when it passes a bunch of stops) and skip ahead 4 or 5 stops or whatever the computer decides is optimal.

Both buses probably need to drop off passengers, though (who would likely be a lot more enraged than people who don't get picked up by the first bus if they didn't get out where they wanted). Anyway, I think the leading bus skips stops when possible, at least here. I don't think people mind that too much, because for all they know, the bus might simply be too full, although that certainly only happens on exceptional…

The London Underground sometimes skips stops in order to uncongest lines after a temporary delay. They tell everyone on the trains that will be skipping stops that it's happening, and anyone who wants the intermediate stops has to get off and catch the next one.

This probably wouldn't work for buses that take a lot longer to load/unload though...

Re: Why Do Buses Bunch?

#50

Post by vecter »

kilbuz wrote: post #40
bobthepanda wrote: post #5

It is also worth noting that in real life passengers are not uniformly distributed through time. When school lets out, or a train arrives at the station full of transfer passengers, etc. you can get a huge burst of traffic at one stop that screws up everything. This can have knockback effects, because if buses show up late to their terminal they have now also started their return trip late. EDIT: edited a word

Not to be a pedant (too late), but you probably meant 'uniformly distributed' in this case.

Not pedantic at all, this is a very crucial distinction.
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