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Comment by sebstefan | Hacker News Reader

>Planners can set minimum and maximum amounts of time to be spent at each stop, and buses might even be told to skip certain stops during crowded runs

>Passengers might be encouraged to wait for a following bus, with the inducement that it’s less crowded.

>Northern Arizona University improved its service by abandoning the idea of a schedule altogether and delaying buses at certain stops in order to maintain even spacing.

FYI the real solution is bus lanes so busses don't get stuck in traffic. But for that, you need to make space that isn't for cars. So you won't get it in Arizona.

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In Spain most city roads with 2+ lanes per direction have a dedicated bus lane, yet you still get bus bunching and spacing adjustments anyways.

- Imagine bus A is followed by bus B, it's 5PM and people are leaving work simultaneously

- Bus A spends a lot of time on each stop picking passengers up

- When bus B arrives, fewer people are waiting and it tends to take less time

- Eventually, bus B catches up to bus A so A must skip stops to maintain proper spacing

As for why this doesn't annoy people: if both buses are already close together, any ETA changes from spacing adjustments are minimal, and bus A will show no destination on the front display, so no false expectations are created.

If there's bus lanes the bunching happens much more slowly. You fix it by giving slightly more time than needed to the busses for their routes on the schedule, say, 20 seconds per stop. That way if they lost some time on some stops, they fetch it back later. With the inconvenience that all the routes take longer

Could you standardize the dwell time? Hit a max and then maintain regularity

except that bus A must often go to stops that it would skip, if any of the passengers want to get off there.

Bunching also happens on things like subway lines that have no other traffic. Many passengers are irrational about forcing their way onto already overcrowded trains.

>Many passengers are irrational about forcing their way onto already overcrowded trains.

the train that leaves first gets there first

----

although, entering a station once with a friend, we ran for an arriving subway train with a friend. they got on but I did not. however, I was familiar with the station we were in, and the destination station and I realized....

so I ran down the platform, continuing in the same direction, and before I reached the other end of the platform, as I expected, the follow-on train arrived. I boarded it, and now I was ahead of my friend schedulewise: blew their mind when I was waiting for them to exit at the destination station.

> the train that leaves first gets there first

I understand this is what motivates people, and I also understand that, when asked, they would claim that this is in their rational self-interest. As I also wrote elsewhere, I tend to disagree or at least question this assumption in general. Are you really in that much of a hurry? If you have a very hard deadline, wouldn't it have been in your rational self-interest to leave home five minutes earlier? etc.

> the train that leaves first gets there first

Yeah, but in this bunching scenario I prefer taking a train with lots of space than arriving maybe two minutes earlier packed like a sardine. Having screens which also show when the following trains will arrive helps a lot of course...

I don't understand how this is possible. Trains are single track in most subways and metros, and definitely do not stop before an already waiting train.

I think the implication is that the time between two trains was little more than the time it took to walk along the whole platform, which the friend still had to do after getting off, plus someone familiar with the stations not needing time to orient themselves and find the intended exit.

they climbed on the last car of the first train

i ran down the platform and, without any other waiting, climbed on the first car of the next train

they got off the last car of the first train and started to walk in the same direction as the train. while they were walking, the first car of the next train, me, rolled well past them before stopping.

Tell me you don't take public transit without telling me you don't take public transit

Getting on the train that's physically in front of you, no matter how crowded, is the rational decision basically everywhere outside Japan, where you can have metaphysical certitude that the next train will show up as scheduled.

It's not, when you know through announcements that the next train is right behind it and will be much less crowded.

It's not as irrational as all that.

Subway system here has an amazing propensity to send random trains on express tracks, especially during peak traffic. I understand that this is done to alleviate congestion, but the net effect is that when you see a train going somewhere you want, you _seize the opportunity_.

It's a coordination problem - taken in isolation, it's not irrational. If only you refrain from doing it, and 37 other people do, you will still have to wait for the next train, and the train in front of you will be almost as late anyways.

The wait for the next train is one factor, the overcrowding is another one. I'm usually not in such a hurry that a minute's wait would make a difference. But the next train is very likely to be much less crowded and much more comfortable to ride on. From my point of view the decision is clear, in isolation, just from my own selfish point of view. And I think many others are making a choice that makes them unhappy. (Train systems differ, the one where I live has sufficient capacity that you rarely get two overcrowded ones back to back. I know there are places where this does not apply.)

> a minute's wait

Is your subway system running trains every 1-2 minutes (30-60 trains per hour)? Mine has trains at 5-8 minute spacing at peak times and 8-12 minutes off-peak.

No, it's running at 3-5 minutes at peak times. But bunching significantly shortens the interval between the delayed, overcrowded train and the empty one right behind it.

Bus lanes exasperate this problem by fast tracking buses to common choke points. It's one of the very few disadvantages of bus lanes.

What causes the choke points?

Passengers getting on and off, intersections, other buses.

Busses stopping or slowing down at intersections is a bug that should be fixed. Other busses is a symptom of the problem, not the cause.

Passengers getting on and off can be a cause, but that is probably a symptom of boarding accessibility issues.

Yes, as long as buses don't travel in public or pick up passengers, they'll be extremely efficient.

What?

Another element is fast fare payment. The faster you can load passengers the lower the penalty for every stop the better

This involves smart cards and fast electronic payment methods. Also removing or discouraging cash payments.

It also might involve designing buses and stops to get people on/off buses faster

I miss tokens. CTA used to use them. Dropping a token in the fare box as you got on the bus was faster than any app or smart card.

> FYI the real solution is bus lanes

The article literally shows that the problem is crowds of people. After work you have 40 people queuing for bus b at every stop so bus c catches up. traffic congestion would mostly affect both buses.

The article shows no such thing. The crowds of people are not the root cause most of the time - if the buses would come at regular intervals, statistically they would all have the same delay because of passengers. But if a bus is already delayed ("if Bus B is delayed by traffic congestion, it incurs a penalty"), there will be more people waiting, which will slow boarding, which leads to more delays, which leads to even more people waiting at the next station etc. But of course, the cause for the initial delay is not always traffic congestion, it can also be a bus breaking down, a large group (e.g. a school class) boarding the bus etc. So dedicated bus lanes (and other measures such as buses/trams being able to influence traffic lights) can't completely eliminate bunching.

Maybe you haven't seen a big crowd. During the day there can be such crowds going to work after 7am that bus must wait for ages then complete cutoff at 9am then some bumps around lunch then another craze at 4-6pm and this even without irregular local events like as you say groups of students

Bus lanes are good but it's driven by crowd sizes and a lot of combatting bunching can be done without adding bus lanes

Where I live the interval at around 7 am is 10 minute, which drops to 15 after 9 am or something and is 20 at the most chill times. Haven't ever seen an empty bus or really overcrowded one either.

Where I lived recently the interval at peak is like 4 min most. One stop boarding can take 3 min when stop is full. My bus skipped my stop until 9am because bus after bus are full. Skipping stops is one way to reduce bunching I guess

EDIT Who said there's only buses? There are cars, taxies and subway

It's always possible to add more buses or people can just go queue at the previous bigger stop it's 2 min walk away and it always stops there.

The point is that crowds cause bunching. I don't know what is your point

That sounds like it's at capacity and buses alone don't cut it anymore.

> FYI the real solution is bus lanes so busses don't get stuck in traffic

The real solution is to stop using transit to move human misery from one place to another. Get everyone an individual car (a self-driving at this point EV, of course) and redesign cities to be human-oriented, not transit-focused.

There is NO mathematical way to make buses robust. They will always be some combination of too slow, too expensive, or too inconvenient for most people.

Buses have low average speed because they need to stop often. And you can't make bus stops more infrequent, because people won't be able to walk from their homes fast enough. And doing complicated systems with local/express buses just wastes time during transit.

Buses can't be frequent, because the average daily load is already just around 15 people per bus. And this is with longer off-peak intervals.

Etc.

> Get everyone an individual car (a self-driving at this point EV, of course) and redesign cities to be human-oriented, not transit-focused.

These two things are in direct, violent contradiction. Mass transit is what allows human-oriented city design. Individual traffic requires car-centric, human-hostile design.

> Mass transit is what allows human-oriented city design.

What exactly is "human" in dense human anthills with 30-story towers?

> Individual traffic requires car-centric, human-hostile design.

Cars have people inside them. And unlike buses, cars allow people to have much more living space, cars are available at any time of day and night, you don't have to wait for a car for 30 minutes, etc.

Cars are human-friendly! Far more so than ANY other transit mode.

And cities should be built for humans, not for transit and bikes.

> What exactly is "human" in dense human anthills with 30-story towers?

Living with and regularly interacting with "people" instead of living in a personal convenience store.

> Cars have people inside them.

Cars kill people. A lot. Like, orders of magnitude more than literally anything other mode of transportation. If you die in a car, it was almost certainly the fault of a driver. If you die walking or cycling, it was almost certainly the fault of a driver. Cars a human-hostile in the most literal sense. Cars kill people. The solution to the problem of cars killing people is not putting more people in cars, because cars are happy to kill people in cars. Because cars kill people.

> And unlike buses, cars allow people to have much more living space

Please elaborate on this. What does "living space" mean to you?

> cars are available at any time of day and night, you don't have to wait for a car for 30 minutes, etc.

Buses only exist because so much money has been spent on car infrastructure, and they are the only mode of public transportation that can directly use that car infrastructure. Once you stop spending insane amounts of money on car infrastructure, more reliable transit can be built (trams, subways, heavy rail, cycling infrastructure, walking infrastructure).

> Cars are human-friendly! Far more so than ANY other transit mode.

Have you - heck, have anyone you know - ever made a friend while driving? Or does human-friendly not include being friendly with humans?

> And cities should be built for humans, not for transit and bikes.

Kachow!

> What exactly is "human" in dense human anthills with 30-story towers?

Certainly an interesting question, but completely irrelevant to the discussion. Unless you're really arguing against big cities rather than against mass transit, but that's an entirely different discussion.

> Cars are human-friendly! Far more so than ANY other transit mode.

No. Cars are human-hostile. Far, FAR more so than ANY other transit mode. Foir one thing, they kill FAR more people than any other transit more. But also because they require So. Much. More Space.

Sure, it's nice to have your own private space while moving around (not worth much when you have to concentrate on driving and are thus stressed, but let's assume that will be alleviated by self-driving cars) but you're not alone. There are 100,000 people who also want to move in the same space. And thus everyone gets a big upside once and a downside that is small but multiplied by 99,999.

The result is this: https://i.dailymail.co.uk/i/pix/2018/02/07/16/48F74A0F000005...

And this: https://lede-admin.usa.streetsblog.org/wp-content/uploads/si...

Now does that look human-friendly to you?

> And cities should be built for humans, not for transit and bikes.

But what you're arguing for is to build them for cars instead. And we have done that and we know the result is horrible. And whe have done the other options too, and we know they are much better.

>What exactly is "human" in dense human anthills with 30-story towers?

You don't really need 30 story towers to have mass transit. Row houses with 3 stories and a few apartment complexes here and there is enough density to not spend forewer to get somewhere and also not necessarily need a car.

None of the claims in this comment are grounded in reality.

On the contrary. I have researched every statement behind them, and ran simulations to prove them. And I was not actually the first person to do that, what I said is well known.

Urbanists just prefer not to talk about it, it complicates the propaganda. After all, urbanism is supposed to have no downsides. It's like violence: if it's not helping, you're not doing enough of it.

Some evidence to support your statements would be very helpful.

As much as I hate buses (trams are better), you seem to hate people more. Society doesn't have to accommodate such tendencies.

No. I want people to be happy and the society to flourish.

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