6 ms·

Is there any merit to the argument that increasing population density will make bad traffic exponentially worse?

wutbrodo 10y ago
I can't imagine there wouldn't be, which is why a sane transit policy is also required. It's a slightly over-simplified but fairly-explanatory model to say that every mile traveled in a car is a failure of transit policy.
erispoe 10y ago
No. Because increased density goes with less reliance on individual cars. The majority of people (by far) in NY or SF don't have a car already. Traffic is not bad in the densest cities of the western world, because we have much more efficient ways of moving people around: public transit. But you also need density to sustain public transit. So you have sour spot where there's not enough density to have good public transit, but enough to create bad traffic. Edit: see below, it's actually the majority of new households that don't have a car in many large American cities, except for NYC, in majority car-free.
- ghaff 10y ago
  About 30% of households in San Francisco do not own cars.[1] That's not the majority "by far." NYC is the only city in the US where the majority of households do not own a car (~56%). But "by far" still only really applies to Manhattan. [1] https://en.wikipedia.org/wiki/List_of_U.S._cities_with_most_households_without_a_car https://en.wikipedia.org/wiki/List_of_U.S._cities_with_most_...
  - cowsandmilk 10y ago
    In the most dense part of NYC, Manhattan, 73% of people don't have access to a car[1], which supports the idea that with more density comes less car dependence/ownership. [1] https://factfinder.census.gov/bkmk/table/1.0/en/ACS/15_5YR/S0801/0600000US3606144919 https://factfinder.census.gov/bkmk/table/1.0/en/ACS/15_5YR/S...
    - L_Rahman 10y ago
      But this is true only if there's enough public infrastructure to support that kind of living. I'm in the East Village and I have these subways in a 10 min walk radius: 4|5|6|N|Q|R|B|D|F|M|L I can make a no transfer trip to anywhere in Manhattan and most parts of Brooklyn and Queens. If I lived in a part of Manhattan or NYC that didn't have these levels of access, I'd be very tempted to get a car.
      - lloyd-christmas 10y ago
        I lived on a block just about the furthest from any subway in manhattan: 81st and York[0]. A car never crossed my mind. http://iquantny.tumblr.com/post/99544282749/found-the-manhattan-apartment-thats-the-farthest http://iquantny.tumblr.com/post/99544282749/found-the-manhat...
  - Tiksi 10y ago
    To be fair, of those in the outer boroughs of NY that do have a car, (anecdotally) they don't commute with it. From what I've seen, the car is for trips out of the city or occasionally getting something big home, or used as part of their job (Taxi, Contractor truck/van, etc).
  - erispoe 10y ago
    You're right. I mixed up my stats. Most of the new households come in these cities without owning a car. Sources: http://sf.streetsblog.org/2014/08/15/car-free-households-are-booming-in-san-francisco/ http://sf.streetsblog.org/2014/08/15/car-free-households-are... https://ggwash.org/view/35905/88-of-new-dc-households-are-car-free https://ggwash.org/view/35905/88-of-new-dc-households-are-ca... http://www.betterinstitutions.com/blog/2013/07/almost-all-of-los-angeles-growth-is-in http://www.betterinstitutions.com/blog/2013/07/almost-all-of...
    - ghaff 10y ago
      That doesn't surprise me much. A disproportionate percentage of new grads moving to Cambridge or Boston to live probably have a job there. Someone working out at 495 would maybe prefer to live in the city but they'd just as soon not have an hour commute each way every day. Furthermore, recent students are used to dealing with not having cars in many cases--even if it can be inconvenient at times. In addition, Zipcar and Uber/Lyft/etc. absolutely make a difference at the margins if you don't need a car on a day-to-day basis.
  - imgabe 10y ago
    Having a car and using a car two different things. I live in a city and own a car, but bike almost everywhere I go.
- loafa 10y ago
  But the biggest cities in the world have problems with foot traffic and subway traffic. I'm not sure that they still employ "pushers" in Tokyo but they very well might. And that's with the benefit of Japanese culture where people are generally clean and polite. Japanese density plus American social problems sounds hellish.
  - cylinder 10y ago
    Yeah all this pro density hype comes off as coming from newbies to big dense cities. High density sucks for quality of life really quickly. Especially peak hours on the subway! I've learned I prefer medium density: walk to a shopping precinct for a commuter train to CBD and essential amenities. Weekends a small car to get about to social stuff, run errands, larger shopping trips, etc. You can have this even in suburban settings by planning well and keeping lot sizes smaller. Hardly exists in the US though.
    - mahyarm 10y ago
      Long commutes and rush hour also sucks in low density suburban america too. I think a lot of the bad sides of high density living for people are unwanted solicitors, bad/old non-soundproofed housing and insecure shipping receiving.
      - vonmoltke 10y ago
        > Long commutes and rush hour also sucks in low density suburban america too. Depends on where you want to live. I lived in Dallas for just over 14 years and never had a commute that was over 30 minutes each way. Half the time I was there it was 15 minutes door-to-desk. Now that I'm in the NYC area it's 1+ hour each way and I'm beholden to a bus or train schedule. I could cut it at the expense of increased rent and less space, but that is not a trade-off my wife and I are willing to make.
        mahyarm 10y ago
        I guess your wealthier in Dallas than you are in NYC in a way? A short commute usually costs more than a long one.
- deleted 10y ago
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Tiktaalik 10y ago
No because the size of roads in urban areas is fixed. Traffic will reach the carrying capacity of the roads and the incentives to drive get worse and worse and people will choose alternatives to driving. If roads and highways are expanded then traffic will increase.
bluGill 10y ago
Density should enable walking which changes everything. A farmer in the middle of nowhere (US or Canada - other countries have different situations that I cannot comment on) is looking at more than 30 minutes to the nearest grocery store if he drives. To walk would be 10 hours each way. As we go down we hit the suburbs - 10 minutes to the store, but still 2 hours to walk. (if you took the same route as the car it would be about an hour, but that means walking on a busy road with no sidewalks, so you end up having to take a much longer route) High density allows stores and restaurants to exist just to serve the people within a couple blocks. You take the elevator downstairs, and within a couple blocks is everything you need to buy, and the job you need to earn money to buy it with. When this is the world you rarely drive anywhere so you are not adding to congestion. Now there is still congestion all those stores/business need to be provided with goods to sell. However a truck that takes up 4 cars worth of space is bringing enough goods to last 400 people for the day, where the cars in the other examples where for 1 person (all facts in this sentence were made up - they seem reasonable but I don't know how to find the right ones). This limits how dense we can get with just surface streets. Note that the above is a should. Zoning laws often put high density far enough away from stores that you have to drive anyway - this makes congestion worse.
- Jtsummers 10y ago
  Ideally you get to mixed use buildings. Ground and maybe first floor dedicated to businesses (shops, offices, gyms, etc.), everything above is residences. Not for every building, you'll still have highrise office buildings (because you need that density of workspaces still, and their ground and first floor will be their local restaurants and gyms and such). But now the average person can get to a small grocery within 100-200m, and a larger one within 500m. Busses can be more effective for transporting people between regions of high residential density to areas of higher office/industrial or shopping density (primarily used by shops carrying non-daily purchase items or requiring more space).
- paulddraper 10y ago
  Grocery store is an interesting example. I've never lived in a dense city so I don't know how this is done. I doubt I could carry a week of groceries for my modest family (2 adults, 2 children) 1 block, let alone several. Do you maybe use personal carts or what?

I can't imagine there wouldn't be, which is why a sane transit policy is also required. It's a slightly over-simplified but fairly-explanatory model to say that every mile traveled in a car is a failure of transit policy.

erispoe 10y ago

No. Because increased density goes with less reliance on individual cars. The majority of people (by far) in NY or SF don't have a car already. Traffic is not bad in the densest cities of the western world, because we have much more efficient ways of moving people around: public transit. But you also need density to sustain public transit. So you have sour spot where there's not enough density to have good public transit, but enough to create bad traffic. Edit: see below, it's actually the majority of new households that don't have a car in many large American cities, except for NYC, in majority car-free.

ghaff 10y ago
About 30% of households in San Francisco do not own cars.[1] That's not the majority "by far." NYC is the only city in the US where the majority of households do not own a car (~56%). But "by far" still only really applies to Manhattan. [1] https://en.wikipedia.org/wiki/List_of_U.S._cities_with_most_households_without_a_car https://en.wikipedia.org/wiki/List_of_U.S._cities_with_most_...
- cowsandmilk 10y ago
  In the most dense part of NYC, Manhattan, 73% of people don't have access to a car[1], which supports the idea that with more density comes less car dependence/ownership. [1] https://factfinder.census.gov/bkmk/table/1.0/en/ACS/15_5YR/S0801/0600000US3606144919 https://factfinder.census.gov/bkmk/table/1.0/en/ACS/15_5YR/S...
  - L_Rahman 10y ago
    But this is true only if there's enough public infrastructure to support that kind of living. I'm in the East Village and I have these subways in a 10 min walk radius: 4|5|6|N|Q|R|B|D|F|M|L I can make a no transfer trip to anywhere in Manhattan and most parts of Brooklyn and Queens. If I lived in a part of Manhattan or NYC that didn't have these levels of access, I'd be very tempted to get a car.
    - lloyd-christmas 10y ago
      I lived on a block just about the furthest from any subway in manhattan: 81st and York[0]. A car never crossed my mind. http://iquantny.tumblr.com/post/99544282749/found-the-manhattan-apartment-thats-the-farthest http://iquantny.tumblr.com/post/99544282749/found-the-manhat...
- Tiksi 10y ago
  To be fair, of those in the outer boroughs of NY that do have a car, (anecdotally) they don't commute with it. From what I've seen, the car is for trips out of the city or occasionally getting something big home, or used as part of their job (Taxi, Contractor truck/van, etc).
- erispoe 10y ago
  You're right. I mixed up my stats. Most of the new households come in these cities without owning a car. Sources: http://sf.streetsblog.org/2014/08/15/car-free-households-are-booming-in-san-francisco/ http://sf.streetsblog.org/2014/08/15/car-free-households-are... https://ggwash.org/view/35905/88-of-new-dc-households-are-car-free https://ggwash.org/view/35905/88-of-new-dc-households-are-ca... http://www.betterinstitutions.com/blog/2013/07/almost-all-of-los-angeles-growth-is-in http://www.betterinstitutions.com/blog/2013/07/almost-all-of...
  - ghaff 10y ago
    That doesn't surprise me much. A disproportionate percentage of new grads moving to Cambridge or Boston to live probably have a job there. Someone working out at 495 would maybe prefer to live in the city but they'd just as soon not have an hour commute each way every day. Furthermore, recent students are used to dealing with not having cars in many cases--even if it can be inconvenient at times. In addition, Zipcar and Uber/Lyft/etc. absolutely make a difference at the margins if you don't need a car on a day-to-day basis.
- imgabe 10y ago
  Having a car and using a car two different things. I live in a city and own a car, but bike almost everywhere I go.
loafa 10y ago
But the biggest cities in the world have problems with foot traffic and subway traffic. I'm not sure that they still employ "pushers" in Tokyo but they very well might. And that's with the benefit of Japanese culture where people are generally clean and polite. Japanese density plus American social problems sounds hellish.
- cylinder 10y ago
  Yeah all this pro density hype comes off as coming from newbies to big dense cities. High density sucks for quality of life really quickly. Especially peak hours on the subway! I've learned I prefer medium density: walk to a shopping precinct for a commuter train to CBD and essential amenities. Weekends a small car to get about to social stuff, run errands, larger shopping trips, etc. You can have this even in suburban settings by planning well and keeping lot sizes smaller. Hardly exists in the US though.
  - mahyarm 10y ago
    Long commutes and rush hour also sucks in low density suburban america too. I think a lot of the bad sides of high density living for people are unwanted solicitors, bad/old non-soundproofed housing and insecure shipping receiving.
    - vonmoltke 10y ago
      > Long commutes and rush hour also sucks in low density suburban america too. Depends on where you want to live. I lived in Dallas for just over 14 years and never had a commute that was over 30 minutes each way. Half the time I was there it was 15 minutes door-to-desk. Now that I'm in the NYC area it's 1+ hour each way and I'm beholden to a bus or train schedule. I could cut it at the expense of increased rent and less space, but that is not a trade-off my wife and I are willing to make.
      - mahyarm 10y ago
        I guess your wealthier in Dallas than you are in NYC in a way? A short commute usually costs more than a long one.
deleted 10y ago
[deleted]

Tiktaalik 10y ago

No because the size of roads in urban areas is fixed. Traffic will reach the carrying capacity of the roads and the incentives to drive get worse and worse and people will choose alternatives to driving. If roads and highways are expanded then traffic will increase.

bluGill 10y ago

Density should enable walking which changes everything. A farmer in the middle of nowhere (US or Canada - other countries have different situations that I cannot comment on) is looking at more than 30 minutes to the nearest grocery store if he drives. To walk would be 10 hours each way. As we go down we hit the suburbs - 10 minutes to the store, but still 2 hours to walk. (if you took the same route as the car it would be about an hour, but that means walking on a busy road with no sidewalks, so you end up having to take a much longer route) High density allows stores and restaurants to exist just to serve the people within a couple blocks. You take the elevator downstairs, and within a couple blocks is everything you need to buy, and the job you need to earn money to buy it with. When this is the world you rarely drive anywhere so you are not adding to congestion. Now there is still congestion all those stores/business need to be provided with goods to sell. However a truck that takes up 4 cars worth of space is bringing enough goods to last 400 people for the day, where the cars in the other examples where for 1 person (all facts in this sentence were made up - they seem reasonable but I don't know how to find the right ones). This limits how dense we can get with just surface streets. Note that the above is a should. Zoning laws often put high density far enough away from stores that you have to drive anyway - this makes congestion worse.

Jtsummers 10y ago
Ideally you get to mixed use buildings. Ground and maybe first floor dedicated to businesses (shops, offices, gyms, etc.), everything above is residences. Not for every building, you'll still have highrise office buildings (because you need that density of workspaces still, and their ground and first floor will be their local restaurants and gyms and such). But now the average person can get to a small grocery within 100-200m, and a larger one within 500m. Busses can be more effective for transporting people between regions of high residential density to areas of higher office/industrial or shopping density (primarily used by shops carrying non-daily purchase items or requiring more space).
paulddraper 10y ago
Grocery store is an interesting example. I've never lived in a dense city so I don't know how this is done. I doubt I could carry a week of groceries for my modest family (2 adults, 2 children) 1 block, let alone several. Do you maybe use personal carts or what?