Live data from Hacker News

Why Do Buses Bunch?

setosa.io

11–20 of 153 posts

Re: Why Do Buses Bunch?

#13
This happens all of the time in Boston, especially with the bigger bus lines. No number 1 bus for 30 minutes, then 3 or 4 of them. Regardless of the cause, it's very frustrating as a passenger from a UX standpoint.

Re: Why Do Buses Bunch?

#14

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…

Same happens in Seattle (and we have some nice services that show you the GPS locations of all the busses on the route, so you can be pretty sure an empty one is right on its way)

Re: Why Do Buses Bunch?

#15
How buses bunch is fairly ovious: the trailing bus has few people to pick up so it moves faster, uselessly catching up to the full bus.

Why they bunch up is actually a different reason: the operators don't give a darn about sticking to schedules and/or tracking the other buses and maintaining space.

Re: Why Do Buses Bunch?

#16
post #9

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!

Buses have to let people off, as well as on, no?

Buses don't stop at unoccupied bus-stops, unless someone dings the bell.

The faster bus skipping stops where people are waiting, so they can be picked up by the next bus does work; I've seen it in action.

Re: Why Do Buses Bunch?

#18

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…

If you're at a bad rail stop (like the first one outside of the central part of a city going outbound at rush hour) it's not uncommon to have to wait two or three trains just to be able to board. In a city like Singapore or London it might not be too long since many of their trains are automated (in Singapore they're all automated/driverless) and the busy lines are allocated enough cars to arrive 1 minute apart or less apart.

Even in cities like Chicago where they arrive 3~5 minutes apart at rush hour, you might still be waiting 30 minutes .. like I was yesterday. ... I really prefer finding crap to do in the city or people to hang out with so I can wait out the rush.

Re: Why Do Buses Bunch?

#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, the bus behind it will always miss out on the customer potential that the first bus is carrying (so five people on that first stop), this will lower its loading time and cause it to gain time and run ahead of schedule - further lowering the loading time.

What can happen with longer commuterish buses is that the first bus can try and counter this effect by either pulling ahead/behind a stop and unloading passengers only, or by skipping stops if no one wishes to disembark, this shifts the load over to the later bus and can equalize the system - but this sort of thing happens all the time.

Additionally, even without that issue, buses are variable, they usually run in the same lanes as traffic and can be delayed for other reasons, high frequency (2,3,4,5 minute lines) will often have a speed deviation that exceeds the frequency, leading to the common effect of waiting six minutes for a 3 minute frequency bus.

Post reply on HN