6 ms·

Unintended road experiments – how kids cause traffic

35 points by winslett 10y ago

Doctor_Fegg 10y ago
Without wanting to sound too snarky - no kidding, Sherlock. Anyone who drives at rush hour in the summer months, when (UK, at least) schools are on holiday, will know how much quieter the roads are. Come September, and it's back to the jams.
- wink 10y ago
  I don't buy that argument completely. Where I went to school, not so many kids were driven to school by car (and much less drove there themselves) - but during the 6 weeks summer vacation everything was a bit quieter, not only during rush hour. But also most people with kids spent their summer vacation away during that time. And also some amount of people without kids still want to use that time for vacation.
  - Declanomous 10y ago
    I think it's enough data to form an interesting hypothesis, but a lot more data would be needed to support that claim. I've often noticed that my commute is much faster on days without school in Chicago, especially my commute home. I think an equally plausible explanation is that people without kids plan necessarily plan their entire schedule around them. For instance, if there is a school inservice, is traffic better because people aren't taking their kids to school, or is traffic better because people stay home with their children? Another thing is that school holidays tend to be local government holidays as well. The local government is one of the largest employers in almost any jurisdiction. If the kids aren't in school because of a holiday or a severe weather event, there's a pretty good chance employees of the local government are not going in to work, not to mention the fact that the school staff probably are probably also not going to work. The research wouldn't be that hard once you had some data, but of course, gathering data is the hardest part of most research.
  - emodendroket 10y ago
    Even if no parents drove their children anywhere the buses everyone has to stop for are a big disruption.
    - Naritai 10y ago
      I don't think the author is asserting it's really driving kids around that causes the traffic. Rather, it's that all parents _need_ to leave their work at (say) 5 in order to get home for their kids.
      - wink 10y ago
        I was not disputing what the author wrote, but what the parent to which I replied posted. In my example, school ended at 1pm or 3 pm, I'd wager not many parents came home, unless they were working part-time or were stay-at-home. I doubt this has changed so much in the last 15 years (since I graduated) although they've switched to 1 year less (so longer lessons) but they're switching back. I simply think that "one American town with ~200k people" is not a very good data point. Also, I have no clue how school in the UK works, maybe people are driving their children to school everyday. :)
      - emodendroket 10y ago
        Fair enough but I think the point about the buses being disruptive all on their own still stands.
    - deleted 10y ago
      [deleted]
- Arizhel 10y ago
  >Without wanting to sound too snarky - no kidding, Sherlock. >Anyone who drives at rush hour in the summer months, when (UK, at least) schools are on holiday, will know how much quieter the roads are. The problem is, "everyone knows" is not scientific reasoning. After all, everyone knows that you only use 10% of your brain, that lightning never strikes the same place twice, and that Napoleon was short. However, all these things are absolutely wrong. So we frequently see things like this where someone takes a "commonly known" hypothesis and uses scientific data to either refute it or support it.
  - cortesoft 10y ago
    Napoleon was 5'6", and that is short. I don't care about 'average height for the time', that just means the average guy was short.
    - Zenst 10y ago
      When 6' is classed as tall then is 5'6" really classed as short by standards, even for that time? Again that is based upon others in that country and average heights per country do vary greatly and in some countries Napoleon would be classed as average or indeed tall. Though personally I would not class him as short.
    - mikeash 10y ago
      I can't find a single worldwide figure, but looking at the average heights per country here, I suspect that 5'6" is about average for a man at present: https://en.wikipedia.org/wiki/List_of_average_human_height_worldwide https://en.wikipedia.org/wiki/List_of_average_human_height_w...
      - cortesoft 10y ago
        Ok, so the average guy is STILL short.
        jmts 10y ago
        Unfortunately Mr Wadlow, I think you'll find that the average guy is, well, average.
- Zenst 10y ago
  I concur with that observation (UK) completely and it is alas down to the shift of families owning two cars more than anything else. Alas we now have whole generations of children who do not walk to school and this is in a time in which school selection now means that the students are more able to have a school nearer home than the past (or course always exceptions and the countryside always has that aspect). This not only has a very noticeable impact upon roads (at a time they are least able to accommodate traffic and add to the problem and pollution) but also has seen a rise in child obesity and alas the way this is tackled is by things like sugar tax, that penalizes everybody. Then again you have the same with alcohol, few people drink to much so they want to introduce a minimum price per unit of alcohol to combat that and again, penalise everybody at the expense of the few. But if a Government can be `seen` to be addressing a problem by adding a TAX over promoting and encouraging a more healthy lifestyle like kids walking to school, then they always go for the TAX option, sadly. Now what really is a sad situation is many parents drive there kids to school as they feel the roads are not safe with all the traffic, that in itself only add's to the issue and befuddles me, mentality wise. Maybe time to suggest to goverments that cars should be taxed if a family own's more than one. I'm sure they would jump at that option as they so love to use TAX as a solution. But until then, I love school holidays as it is the only time in which the roads are so much easier and quicker to navigate and that is from a public transport bus perspective alone. One journey I used to make would take an hour during school open times and during school holidays would be, between 25-50% quicker. Another interesting observation I have made was that during school holidays nowadays there tends to be more road works, which can offset some gains and that is a trend that becomes more and more prominent. I can only surmise they do this to minimise impact, which only highlights the issue with school run cars without addressing and tacking it in any way, shape or form. Again this is from a UK perspective in the London and surrounding area or urban sprawl and would be interested if the same trends/issues are as common in other countries urban area's.
- jandrese 10y ago
  I have noticed this phenomenon as well, although I'm not sure if it's just the kids being out of school or more people going on vacation because school is out. Or maybe people who were previously trapped at going in during the peak of rush hour due to needing to drop the kids off at the bus first can instead push their commute forward and spread the load. Something is going on and it is correlated with the school year but I don't have enough data to pin down any specific cause.
mikeash 10y ago
"People without kids were largely unaffected." Oh really? The only conclusion supported by the data is that the threat of severe weather alleviates traffic. Pinning it on kids, just because most of the people the author knows still went to work, is nonsense. I'd assume this article was satire, but it's written with such sincerity that I don't think it is.
- winslett 10y ago
  I do recognize I have large gaps of data missing. This was written as a hypothesis on travel and randomness. To support kids activities in a southern US city, random time/source/destination of drivers is removed. Most people have to drive to the same location at the same time to send their kids to school or other activities. Thus, the event yesterday added more randomness to the travel patterns by removing the kids activities. I don't have real-time flow of all data, thus I could be completely wrong. All I have for traffic data is a few Google traffic maps.
  - mikeash 10y ago
    The data is so sparse that we have no idea if the kids were indeed the critical factor, or if they were completely irrelevant and the change was due to something else entirely. It doesn't really read as a hypothesis with statements like "People without kids were largely unaffected." On a somewhat different note, it may not be the same there, but around here (Fairfax County, near DC), school opening times are staggered fairly substantially in order to make better use of the bus fleet. Schools here start anywhere from 7:10AM to 9:20AM. This will also spread out car traffic, not that the school district does that intentionally.
  - conductr 10y ago
    You're not just missing data, you need some ceteris paribus and when severe weather events happens you are very far from it. Randomness does not allow you to validate the conclusion you want or that makes most sense to you. I live in a southern city that occasionally gets ice, vast majority of people take that opportunity to just stay home. Nobody in the south can drive in ice. When that happens. Traffic is light whether school is in session or not. Therefore, I say kids have zero impact on traffic. Ha!
S_A_P 10y ago
My first thought is that this guy has not lived in a populated city during rush hour. Growing up in Houston, its a part of life. As soon as school is out, traffic is reduced by at least 1/3-1/2 on major freeways according to my built in road rage o meter. In suburban hubs, traffic is reduced in the evenings as well but that is more static throughout the year. Just recently during spring break my commute halved in terms of minutes in the car. I see other problems with his "study" as well, since it was a state of emergency, other people stayed home as well since they anticipated terrible weather, so as a datapoint its not very useful.
- NOSHSHNACKERS 10y ago
  word.. because schools close gov agencies close - state and local workers are home
emodendroket 10y ago
Hm, next this guy should look into sporting events.
- brudgers 10y ago
  The author mentions Auburn and Alabama football games in the final paragraph. That's the gridiron pointy ball football not o jogo bonito.
Pxtl 10y ago
"I can't let my kid walk to school, it's too dangerous with all the traffic out there".
drtz 10y ago
I'm sure the author's conclusions have some merit, but the reduction in traffic likely also has a lot do with the fact that a lot of parents who would otherwise be working during the day are instead staying home with their kids.
jressey 10y ago
Oh really?! Cancelling a bunch of peoples' normal activities so they don't have to travel to them reduces traffic. This argument is a tautology.
jmts 10y ago
The amount of ridicule for this post seems rather surprising. This guy had a curiosity and he wanted to quantify it. I'm sure everybody knows that traffic is reduced when school is out. Why should that stop someone from asking why, by what magnitude, and what other interesting things occur during this time? I'd hazard a guess that everybody in the 1600's knew that apples fell to the ground. It took Newton to ask why.
- winslett 10y ago
  Ha! Thanks :) The "genius class" on YCombinator isn't my intended audience. Those folks can go jump off a cliff. My intended audience is the average person who jumps in a car and drives without thinking what is beyond the windshield. I think these people are interesting because they are making to-the-second economic decisions while driving. Given that: * road space is a fixed asset * information about upcoming road conditions is uncertain * people can use devices to gather best-effort information from Google * a driver can only choose one route * the choices drivers collectively makes a market * drivers choose to be risker to save time The write up today is really just a foundational observations. Cheers, Chris
emj 10y ago
Given that "traffic problems are caused by a very slight increase in the amount of cars" it's very obvious why things got calmer if a small portion of the work force had to change their routine. If you are stuck in traffic you have only yourself to blame, you are the traffic.

35 points by winslett 10y ago

Without wanting to sound too snarky - no kidding, Sherlock. Anyone who drives at rush hour in the summer months, when (UK, at least) schools are on holiday, will know how much quieter the roads are. Come September, and it's back to the jams.

wink 10y ago
I don't buy that argument completely. Where I went to school, not so many kids were driven to school by car (and much less drove there themselves) - but during the 6 weeks summer vacation everything was a bit quieter, not only during rush hour. But also most people with kids spent their summer vacation away during that time. And also some amount of people without kids still want to use that time for vacation.
- Declanomous 10y ago
  I think it's enough data to form an interesting hypothesis, but a lot more data would be needed to support that claim. I've often noticed that my commute is much faster on days without school in Chicago, especially my commute home. I think an equally plausible explanation is that people without kids plan necessarily plan their entire schedule around them. For instance, if there is a school inservice, is traffic better because people aren't taking their kids to school, or is traffic better because people stay home with their children? Another thing is that school holidays tend to be local government holidays as well. The local government is one of the largest employers in almost any jurisdiction. If the kids aren't in school because of a holiday or a severe weather event, there's a pretty good chance employees of the local government are not going in to work, not to mention the fact that the school staff probably are probably also not going to work. The research wouldn't be that hard once you had some data, but of course, gathering data is the hardest part of most research.
- emodendroket 10y ago
  Even if no parents drove their children anywhere the buses everyone has to stop for are a big disruption.
  - Naritai 10y ago
    I don't think the author is asserting it's really driving kids around that causes the traffic. Rather, it's that all parents _need_ to leave their work at (say) 5 in order to get home for their kids.
    - wink 10y ago
      I was not disputing what the author wrote, but what the parent to which I replied posted. In my example, school ended at 1pm or 3 pm, I'd wager not many parents came home, unless they were working part-time or were stay-at-home. I doubt this has changed so much in the last 15 years (since I graduated) although they've switched to 1 year less (so longer lessons) but they're switching back. I simply think that "one American town with ~200k people" is not a very good data point. Also, I have no clue how school in the UK works, maybe people are driving their children to school everyday. :)
    - emodendroket 10y ago
      Fair enough but I think the point about the buses being disruptive all on their own still stands.
  - deleted 10y ago
    [deleted]
Arizhel 10y ago
>Without wanting to sound too snarky - no kidding, Sherlock. >Anyone who drives at rush hour in the summer months, when (UK, at least) schools are on holiday, will know how much quieter the roads are. The problem is, "everyone knows" is not scientific reasoning. After all, everyone knows that you only use 10% of your brain, that lightning never strikes the same place twice, and that Napoleon was short. However, all these things are absolutely wrong. So we frequently see things like this where someone takes a "commonly known" hypothesis and uses scientific data to either refute it or support it.
- cortesoft 10y ago
  Napoleon was 5'6", and that is short. I don't care about 'average height for the time', that just means the average guy was short.
  - Zenst 10y ago
    When 6' is classed as tall then is 5'6" really classed as short by standards, even for that time? Again that is based upon others in that country and average heights per country do vary greatly and in some countries Napoleon would be classed as average or indeed tall. Though personally I would not class him as short.
  - mikeash 10y ago
    I can't find a single worldwide figure, but looking at the average heights per country here, I suspect that 5'6" is about average for a man at present: https://en.wikipedia.org/wiki/List_of_average_human_height_worldwide https://en.wikipedia.org/wiki/List_of_average_human_height_w...
    - cortesoft 10y ago
      Ok, so the average guy is STILL short.
      - jmts 10y ago
        Unfortunately Mr Wadlow, I think you'll find that the average guy is, well, average.
Zenst 10y ago
I concur with that observation (UK) completely and it is alas down to the shift of families owning two cars more than anything else. Alas we now have whole generations of children who do not walk to school and this is in a time in which school selection now means that the students are more able to have a school nearer home than the past (or course always exceptions and the countryside always has that aspect). This not only has a very noticeable impact upon roads (at a time they are least able to accommodate traffic and add to the problem and pollution) but also has seen a rise in child obesity and alas the way this is tackled is by things like sugar tax, that penalizes everybody. Then again you have the same with alcohol, few people drink to much so they want to introduce a minimum price per unit of alcohol to combat that and again, penalise everybody at the expense of the few. But if a Government can be `seen` to be addressing a problem by adding a TAX over promoting and encouraging a more healthy lifestyle like kids walking to school, then they always go for the TAX option, sadly. Now what really is a sad situation is many parents drive there kids to school as they feel the roads are not safe with all the traffic, that in itself only add's to the issue and befuddles me, mentality wise. Maybe time to suggest to goverments that cars should be taxed if a family own's more than one. I'm sure they would jump at that option as they so love to use TAX as a solution. But until then, I love school holidays as it is the only time in which the roads are so much easier and quicker to navigate and that is from a public transport bus perspective alone. One journey I used to make would take an hour during school open times and during school holidays would be, between 25-50% quicker. Another interesting observation I have made was that during school holidays nowadays there tends to be more road works, which can offset some gains and that is a trend that becomes more and more prominent. I can only surmise they do this to minimise impact, which only highlights the issue with school run cars without addressing and tacking it in any way, shape or form. Again this is from a UK perspective in the London and surrounding area or urban sprawl and would be interested if the same trends/issues are as common in other countries urban area's.
jandrese 10y ago
I have noticed this phenomenon as well, although I'm not sure if it's just the kids being out of school or more people going on vacation because school is out. Or maybe people who were previously trapped at going in during the peak of rush hour due to needing to drop the kids off at the bus first can instead push their commute forward and spread the load. Something is going on and it is correlated with the school year but I don't have enough data to pin down any specific cause.

mikeash 10y ago

"People without kids were largely unaffected." Oh really? The only conclusion supported by the data is that the threat of severe weather alleviates traffic. Pinning it on kids, just because most of the people the author knows still went to work, is nonsense. I'd assume this article was satire, but it's written with such sincerity that I don't think it is.

winslett 10y ago
I do recognize I have large gaps of data missing. This was written as a hypothesis on travel and randomness. To support kids activities in a southern US city, random time/source/destination of drivers is removed. Most people have to drive to the same location at the same time to send their kids to school or other activities. Thus, the event yesterday added more randomness to the travel patterns by removing the kids activities. I don't have real-time flow of all data, thus I could be completely wrong. All I have for traffic data is a few Google traffic maps.
- mikeash 10y ago
  The data is so sparse that we have no idea if the kids were indeed the critical factor, or if they were completely irrelevant and the change was due to something else entirely. It doesn't really read as a hypothesis with statements like "People without kids were largely unaffected." On a somewhat different note, it may not be the same there, but around here (Fairfax County, near DC), school opening times are staggered fairly substantially in order to make better use of the bus fleet. Schools here start anywhere from 7:10AM to 9:20AM. This will also spread out car traffic, not that the school district does that intentionally.
- conductr 10y ago
  You're not just missing data, you need some ceteris paribus and when severe weather events happens you are very far from it. Randomness does not allow you to validate the conclusion you want or that makes most sense to you. I live in a southern city that occasionally gets ice, vast majority of people take that opportunity to just stay home. Nobody in the south can drive in ice. When that happens. Traffic is light whether school is in session or not. Therefore, I say kids have zero impact on traffic. Ha!

S_A_P 10y ago

My first thought is that this guy has not lived in a populated city during rush hour. Growing up in Houston, its a part of life. As soon as school is out, traffic is reduced by at least 1/3-1/2 on major freeways according to my built in road rage o meter. In suburban hubs, traffic is reduced in the evenings as well but that is more static throughout the year. Just recently during spring break my commute halved in terms of minutes in the car. I see other problems with his "study" as well, since it was a state of emergency, other people stayed home as well since they anticipated terrible weather, so as a datapoint its not very useful.

NOSHSHNACKERS 10y ago
word.. because schools close gov agencies close - state and local workers are home

emodendroket 10y ago

Hm, next this guy should look into sporting events.

brudgers 10y ago
The author mentions Auburn and Alabama football games in the final paragraph. That's the gridiron pointy ball football not o jogo bonito.

Pxtl 10y ago

"I can't let my kid walk to school, it's too dangerous with all the traffic out there".

drtz 10y ago

I'm sure the author's conclusions have some merit, but the reduction in traffic likely also has a lot do with the fact that a lot of parents who would otherwise be working during the day are instead staying home with their kids.

jressey 10y ago

Oh really?! Cancelling a bunch of peoples' normal activities so they don't have to travel to them reduces traffic. This argument is a tautology.

jmts 10y ago

The amount of ridicule for this post seems rather surprising. This guy had a curiosity and he wanted to quantify it. I'm sure everybody knows that traffic is reduced when school is out. Why should that stop someone from asking why, by what magnitude, and what other interesting things occur during this time? I'd hazard a guess that everybody in the 1600's knew that apples fell to the ground. It took Newton to ask why.

winslett 10y ago
Ha! Thanks :) The "genius class" on YCombinator isn't my intended audience. Those folks can go jump off a cliff. My intended audience is the average person who jumps in a car and drives without thinking what is beyond the windshield. I think these people are interesting because they are making to-the-second economic decisions while driving. Given that: * road space is a fixed asset * information about upcoming road conditions is uncertain * people can use devices to gather best-effort information from Google * a driver can only choose one route * the choices drivers collectively makes a market * drivers choose to be risker to save time The write up today is really just a foundational observations. Cheers, Chris

emj 10y ago

Given that "traffic problems are caused by a very slight increase in the amount of cars" it's very obvious why things got calmer if a small portion of the work force had to change their routine. If you are stuck in traffic you have only yourself to blame, you are the traffic.