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When it comes to roads, why is increasing capacity to resolve the capacity problem always automatically dismissed? I know building roads is not politically fash

When it comes to roads, why is increasing capacity to resolve the capacity problem always automatically dismissed? I know building roads is not politically fashionable, but the alternative is to invest billions into poorly designed public transport, and (even worse) cycling infrastructure. Spending which over the course of decades barely manages to move public transport or cycling adoption by a few percent, where ever its implemented. Poor zoning regulation always seems to be a major contributor (to both transport and housing issues), but when your population increases by millions, you need to increase the capacity of your infrastructure, especially roads. The problem is a lack of rationality. A politician that says "I'm going to spend billions on new cycle paths" is somehow going to be more popular than a politician that says "I'm going to spend billions on new roads". Even in cities where cyclists make up <5% of commuters.

ahmedalsudani 9y ago
1. It has been shown that time and again, the volume of car traffic grows to match the increase in capacity, keeping commute time constant. 2. People like to bike, and unlike cars, you can make the case that not very many people bike because the infrastructure doesn’t support biking. If less than 5% of the people are biking, but the politician who promotes biking is popular, that tells you something about reality vs. what people want. 3. Car companies have undermined attitudes that made driving a secondary mode of transportation (not to mention the streetcar conspiracy). It’s due time for a correction that allows North Americans to live a lifestyle less reliant on cars.
flukus 9y ago
> When it comes to roads, why is increasing capacity to resolve the capacity problem always automatically dismissed? Because those people are going somewhere and increasing capacity of one road typically just moves the bottleneck. The only exceptions to this are when the traffic is going through the area with the new capacity and other other side has excess capacity. So something like increasing the capacity on a city bypass will reduce congestion, but increasing capacity into the city wont. The other problem is induced demand (https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand), when driving is quick and easy more people will drive until that's no longer the case. > A politician that says "I'm going to spend billions on new cycle paths" is somehow going to be more popular than a politician that says "I'm going to spend billions on new roads". How many (non-dutch) cities in the world have spent billions on cycle paths? They should be more popular because they're doing something that will actually reduce traffic and save money long term (cycle paths require a lot less maintenance), but IME it's the ones promising new roads that keep getting elected.
nickles 9y ago
> When it comes to roads, why is increasing capacity to resolve the capacity problem always automatically dismissed? There's a large body of evidence [0][1] indicating that adding road capacity does not alleviate congestion. In the short run, one tends to see immediate rises in traffic on the new infrastructure. Over a longer period, the amount of traffic utilizing new infrastructure increases until all added capacity is being consumed. This is known as induced demand [2]. Congestion pricing [3] is a more economically viable manner of reducing congestion on shared infrastructure, but it comes with its own set of concerns [4]. [0] https://www.citylab.com/transportation/2015/11/californias-dot-admits-that-more-roads-mean-more-traffic/415245/ https://www.citylab.com/transportation/2015/11/californias-d... [1] https://www.wired.com/2014/06/wuwt-traffic-induced-demand/ https://www.wired.com/2014/06/wuwt-traffic-induced-demand/ [2] https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand [3] https://en.wikipedia.org/wiki/Congestion_pricing https://en.wikipedia.org/wiki/Congestion_pricing [4] https://www.nytimes.com/2018/04/09/nyregion/congestion-pricing-manhattan-albany-fail.html https://www.nytimes.com/2018/04/09/nyregion/congestion-prici...
- AmericanChopper 9y ago
  All this means is that capacity is so far behind demand that current spending doesn't come close to establishing a reasonable equilibrium. Which is what you'd expect after decades of major population growth, accompanied by infrastructure neglect.
  - nickles 9y ago
    > All this means is that capacity is so far behind demand that current spending doesn't come close to establishing a reasonable equilibrium. I'd hesitate to specify that certain equilibria are reasonable while others are not. Building more roads to reduce congestion does not achieve that goal, in part because of the latent demand you describe (see [0] "Effect in transportation systems"). Ultimately, if your goal is to decrease time spent traveling, you will see more benefit from alternative policies. Such policies may include: * increasing cost of using the roads (e.g. congestion pricing) * constructing alternate, denser forms of public infrastructure (e.g. subways) * increasing the density of passengers in vehicles (buses, carpooling, etc.) * funding technological advances that increase the density of vehicles utilizing the road (e.g. self driving cars) [0] https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand
SllX 9y ago
Because of induced demand. Increasing road capacity can cut commute times, for like a week. When people know they can get somewhere more quickly and more reliably because of increase road capacity, they drive more, which in aggregate, causes the new roads to become as gridlocked as the old roads, and the old roads are still gridlocked. Single occupancy vehicles are just not efficient for moving large numbers of people around. In order of preference you basically want people to 1. not have to commute (telecommute) 2. walk 3. ride a light vehicle (bike, electric scooter, whatever) 4. take a train or Ferry 5. take a shuttle 6. take a bus 7. carpool 8. drive 9. take a plane. (Actually not sure where Lyft and Uber fall in that stack given there's evidence that ridesharing platforms seem to be increasing traffic in the areas they operate in.) Of course you can mix any and all of those but your city's transportation infrastructure ought to accommodate each of them and prioritize each in kind.
- AmericanChopper 9y ago
  Those people don't appear out of thin air, the only reason increasing capacity can be shown to not influence commute times is because such studies look at small increases of capacity followed by decades of no capacity increases at all. They're totally biased. To talk about efficiency, it's also not very efficient to assign a whole dwelling to each family. But that's what people want to have, so you can either plan for that, where you at least have the possibility of success, or you can continue to plan cities based upon utopian fictions, and continue to get the same results.
  - bsder 9y ago
    These results hold whether the city is in California or Texas. If Texas can't build enough roads to solve the problem, no one can. Houston's road system is enormous.
  - TulliusCicero 9y ago
    > But that's what people want to have Are you suggesting that if cities upzoned more areas for smaller dwelling like townhomes and duplexes, families would, what, refuse to live in them? Those units would just remain empty? Because if so, you're wrong. It's not the free market, it's not individual choice blocking smaller dwellings, it's zoning regulations.
dasil003 9y ago
Why do you think cyclists make up <5% of commuters in LA? Hint: it's not because of the weather.
- AmericanChopper 9y ago
  Why are cyclists <5% of commuters in SF, where the local government has invested many billions of dollars into building a perfectly serviceable cycling infrastructure? A pattern which you can see in a number of different cities around the world who have done the same. It's because no matter what people say, they don't want to cycle to work. I read a headline recently that said cycling in SF was up 10%, celebrating the billions spent on the infrastructure, however nowhere in the article did it mention that the 10% increase amounted to a total of ~3.5% commuters on bikes. You don't have to be a genius to figure out that only devoting 50% of your transport budget to the mode used by 90% of the population is not a recipe for success.
  - Doctor_Fegg 9y ago
    Visit London. Cycling is now the majority mode of transport in the City of London rush hour. That’s due to car reduction measures (the Congestion Charge) and new infrastructure both large (Cycle Superhighways) and small (filtered permeability). Your assertion that “people don’t want to cycle to work” is demonstrably false. (Source: https://www.bikebiz.com/news/traffic-in-the-city-2018 https://www.bikebiz.com/news/traffic-in-the-city-2018 )
    - AmericanChopper 9y ago
      In London, cyclists make up less than 5% of commuters. Hardly a vision of success.
      - Doctor_Fegg 9y ago
        Define "London". In inner/central London, where cycling infrastructure is being built and where the Congestion Charge is in place, the cycle commute share is significantly higher than 5%. (Back in 2011, for example, it was 15.4% in Hackney: it will be bigger than that now.) In the outer suburbs, where there's no infrastructure and no Congestion Charge, it isn't above 5%. That should tell you something. Meanwhile, you talk sneeringly about "invest[ing] billions into poorly designed public transport". Public transport is, of course, something London does very well. Car commuting across the whole of London, inner and outer, is around 25%. Public transport commuting is around 50%. (Source: LTDS. This covers London residents only, so is probably an underestimate given the vast numbers of people from outside London who commute into the city by rail.)
TulliusCicero 9y ago
No, the problem is that you appear to be ignorant of the issues: a pittance is spent on transit and biking compared to driving, driving dominates road design, land use regulations are built around driving. "We built everything for cars, and now everyone is driving!" What a shock. The idea that politicians pledge to spend "billions" on biking (and actually do so) is particularly laughable. Where exactly is this biketopia? (It doesn't exist)
- AmericanChopper 9y ago
  They don’t exist, and never will, because outside of the feels cities in the world that are suited for cycling, people don’t actually want them. The cynic in me says that car drivers only support cycle way spending because they think it’ll clear up the roads for them. But the reality is that doesn’t happen. In LA less than 50% of the transit budget is spent on roads, despite them being the primary facilitator of transport. Your position is based entirely upon a utopian fiction, where if only we could tear the whole city down and rebuild it from the ground up, then maybe people would want to bike to work.
  - TulliusCicero 9y ago
    Still waiting for a source on cities like SF having spent "many billions" on bike infrastructure. You really did just make that up, didn't you? Look, if you want a serious discussion, maybe don't, like, lie? > In LA less than 50% of the transit budget is spent on roads, despite them being the primary facilitator of transport. 1. What's the cumulative investment there? LA spent decades building out freeways, after all. It takes a while to turn that ship around. 2. LA is explicitly turning away from car-centric design and spending because it didn't work. They're the poster child for it, and traffic is the worst in the country. Maybe more transit and bike spending won't completely 'solve' traffic, but going by other cities' examples, they should be able to make it less bad.
  - kalleboo 9y ago
    I lived in a city that made a conscious effort to retrofit a bike network with many dedicated routes over the past decade and it has paid off with a massive increase in riders (mode share has passed 20%). There was a corresponding decline in people traveling by car, despite the city also expanding the road network by twice the amount at the same time (they didn't reduce funding).
barrkel 9y ago
People have a specific tolerance curve for commute time and traffic. With more and bigger roads, they gradually work and live further away (where land is cheaper and they can have a bigger house) until the traffic reaches the same critical point again. Excess capacity induces demand, attracts it, by enabling people from further away to consume the capacity.
- humanrebar 9y ago
  > until the traffic reaches the same critical point again Right, but commutable land grows exponentially as roads are improved further from the city center. So, depending on what you value, it's a net win when a twenty minute commute gets you ten miles away instead of five.
stale2002 9y ago
The real solution is to build more housing near where people work, so that people don't HAVE to commute. Oh who am i kidding. Thats politically impossible.
- jurip 9y ago
  How do you propose achieve that for households with more than one person going to work outside their home? That requires being highly selective when accepting job offers and being willing to move and possibly quit jobs often.
  - stale2002 9y ago
    Im suggesting that more houses get built downtown in the city. Not EVERYONE would have to live in the city. A lot are interested, and would move there themselves, and this would cut down on traffic significantly.
    - jurip 9y ago
      Oh, I absolutely agree with building more housing (and office and retail space, etc) and less roads and parking in the city. But that does not eliminate the commute. You have to live in a really small town and/or be very lucky with jobs to not have a noticeable commute. Of course, if you can do that commute on foot, bike or public transit that's better for everyone.
cabalamat 9y ago
> but the alternative is to invest billions into poorly designed public transport Why can't we have well-designed public transport? Edinburgh manages to do this, so I'm sure other cities could if they wanted to. The basic ideas are bus lanes and lots of high-density housing. This would also have advantage of making housing affordable.

ahmedalsudani 9y ago

1. It has been shown that time and again, the volume of car traffic grows to match the increase in capacity, keeping commute time constant. 2. People like to bike, and unlike cars, you can make the case that not very many people bike because the infrastructure doesn’t support biking. If less than 5% of the people are biking, but the politician who promotes biking is popular, that tells you something about reality vs. what people want. 3. Car companies have undermined attitudes that made driving a secondary mode of transportation (not to mention the streetcar conspiracy). It’s due time for a correction that allows North Americans to live a lifestyle less reliant on cars.

flukus 9y ago

> When it comes to roads, why is increasing capacity to resolve the capacity problem always automatically dismissed? Because those people are going somewhere and increasing capacity of one road typically just moves the bottleneck. The only exceptions to this are when the traffic is going through the area with the new capacity and other other side has excess capacity. So something like increasing the capacity on a city bypass will reduce congestion, but increasing capacity into the city wont. The other problem is induced demand (https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand), when driving is quick and easy more people will drive until that's no longer the case. > A politician that says "I'm going to spend billions on new cycle paths" is somehow going to be more popular than a politician that says "I'm going to spend billions on new roads". How many (non-dutch) cities in the world have spent billions on cycle paths? They should be more popular because they're doing something that will actually reduce traffic and save money long term (cycle paths require a lot less maintenance), but IME it's the ones promising new roads that keep getting elected.

nickles 9y ago

> When it comes to roads, why is increasing capacity to resolve the capacity problem always automatically dismissed? There's a large body of evidence [0][1] indicating that adding road capacity does not alleviate congestion. In the short run, one tends to see immediate rises in traffic on the new infrastructure. Over a longer period, the amount of traffic utilizing new infrastructure increases until all added capacity is being consumed. This is known as induced demand [2]. Congestion pricing [3] is a more economically viable manner of reducing congestion on shared infrastructure, but it comes with its own set of concerns [4]. [0] https://www.citylab.com/transportation/2015/11/californias-dot-admits-that-more-roads-mean-more-traffic/415245/ https://www.citylab.com/transportation/2015/11/californias-d... [1] https://www.wired.com/2014/06/wuwt-traffic-induced-demand/ https://www.wired.com/2014/06/wuwt-traffic-induced-demand/ [2] https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand [3] https://en.wikipedia.org/wiki/Congestion_pricing https://en.wikipedia.org/wiki/Congestion_pricing [4] https://www.nytimes.com/2018/04/09/nyregion/congestion-pricing-manhattan-albany-fail.html https://www.nytimes.com/2018/04/09/nyregion/congestion-prici...

AmericanChopper 9y ago
All this means is that capacity is so far behind demand that current spending doesn't come close to establishing a reasonable equilibrium. Which is what you'd expect after decades of major population growth, accompanied by infrastructure neglect.
- nickles 9y ago
  > All this means is that capacity is so far behind demand that current spending doesn't come close to establishing a reasonable equilibrium. I'd hesitate to specify that certain equilibria are reasonable while others are not. Building more roads to reduce congestion does not achieve that goal, in part because of the latent demand you describe (see [0] "Effect in transportation systems"). Ultimately, if your goal is to decrease time spent traveling, you will see more benefit from alternative policies. Such policies may include: * increasing cost of using the roads (e.g. congestion pricing) * constructing alternate, denser forms of public infrastructure (e.g. subways) * increasing the density of passengers in vehicles (buses, carpooling, etc.) * funding technological advances that increase the density of vehicles utilizing the road (e.g. self driving cars) [0] https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand

SllX 9y ago

Because of induced demand. Increasing road capacity can cut commute times, for like a week. When people know they can get somewhere more quickly and more reliably because of increase road capacity, they drive more, which in aggregate, causes the new roads to become as gridlocked as the old roads, and the old roads are still gridlocked. Single occupancy vehicles are just not efficient for moving large numbers of people around. In order of preference you basically want people to 1. not have to commute (telecommute) 2. walk 3. ride a light vehicle (bike, electric scooter, whatever) 4. take a train or Ferry 5. take a shuttle 6. take a bus 7. carpool 8. drive 9. take a plane. (Actually not sure where Lyft and Uber fall in that stack given there's evidence that ridesharing platforms seem to be increasing traffic in the areas they operate in.) Of course you can mix any and all of those but your city's transportation infrastructure ought to accommodate each of them and prioritize each in kind.

AmericanChopper 9y ago
Those people don't appear out of thin air, the only reason increasing capacity can be shown to not influence commute times is because such studies look at small increases of capacity followed by decades of no capacity increases at all. They're totally biased. To talk about efficiency, it's also not very efficient to assign a whole dwelling to each family. But that's what people want to have, so you can either plan for that, where you at least have the possibility of success, or you can continue to plan cities based upon utopian fictions, and continue to get the same results.
- bsder 9y ago
  These results hold whether the city is in California or Texas. If Texas can't build enough roads to solve the problem, no one can. Houston's road system is enormous.
- TulliusCicero 9y ago
  > But that's what people want to have Are you suggesting that if cities upzoned more areas for smaller dwelling like townhomes and duplexes, families would, what, refuse to live in them? Those units would just remain empty? Because if so, you're wrong. It's not the free market, it's not individual choice blocking smaller dwellings, it's zoning regulations.

dasil003 9y ago

Why do you think cyclists make up <5% of commuters in LA? Hint: it's not because of the weather.

AmericanChopper 9y ago
Why are cyclists <5% of commuters in SF, where the local government has invested many billions of dollars into building a perfectly serviceable cycling infrastructure? A pattern which you can see in a number of different cities around the world who have done the same. It's because no matter what people say, they don't want to cycle to work. I read a headline recently that said cycling in SF was up 10%, celebrating the billions spent on the infrastructure, however nowhere in the article did it mention that the 10% increase amounted to a total of ~3.5% commuters on bikes. You don't have to be a genius to figure out that only devoting 50% of your transport budget to the mode used by 90% of the population is not a recipe for success.
- Doctor_Fegg 9y ago
  Visit London. Cycling is now the majority mode of transport in the City of London rush hour. That’s due to car reduction measures (the Congestion Charge) and new infrastructure both large (Cycle Superhighways) and small (filtered permeability). Your assertion that “people don’t want to cycle to work” is demonstrably false. (Source: https://www.bikebiz.com/news/traffic-in-the-city-2018 https://www.bikebiz.com/news/traffic-in-the-city-2018 )
  - AmericanChopper 9y ago
    In London, cyclists make up less than 5% of commuters. Hardly a vision of success.
    - Doctor_Fegg 9y ago
      Define "London". In inner/central London, where cycling infrastructure is being built and where the Congestion Charge is in place, the cycle commute share is significantly higher than 5%. (Back in 2011, for example, it was 15.4% in Hackney: it will be bigger than that now.) In the outer suburbs, where there's no infrastructure and no Congestion Charge, it isn't above 5%. That should tell you something. Meanwhile, you talk sneeringly about "invest[ing] billions into poorly designed public transport". Public transport is, of course, something London does very well. Car commuting across the whole of London, inner and outer, is around 25%. Public transport commuting is around 50%. (Source: LTDS. This covers London residents only, so is probably an underestimate given the vast numbers of people from outside London who commute into the city by rail.)

TulliusCicero 9y ago

No, the problem is that you appear to be ignorant of the issues: a pittance is spent on transit and biking compared to driving, driving dominates road design, land use regulations are built around driving. "We built everything for cars, and now everyone is driving!" What a shock. The idea that politicians pledge to spend "billions" on biking (and actually do so) is particularly laughable. Where exactly is this biketopia? (It doesn't exist)

AmericanChopper 9y ago
They don’t exist, and never will, because outside of the feels cities in the world that are suited for cycling, people don’t actually want them. The cynic in me says that car drivers only support cycle way spending because they think it’ll clear up the roads for them. But the reality is that doesn’t happen. In LA less than 50% of the transit budget is spent on roads, despite them being the primary facilitator of transport. Your position is based entirely upon a utopian fiction, where if only we could tear the whole city down and rebuild it from the ground up, then maybe people would want to bike to work.
- TulliusCicero 9y ago
  Still waiting for a source on cities like SF having spent "many billions" on bike infrastructure. You really did just make that up, didn't you? Look, if you want a serious discussion, maybe don't, like, lie? > In LA less than 50% of the transit budget is spent on roads, despite them being the primary facilitator of transport. 1. What's the cumulative investment there? LA spent decades building out freeways, after all. It takes a while to turn that ship around. 2. LA is explicitly turning away from car-centric design and spending because it didn't work. They're the poster child for it, and traffic is the worst in the country. Maybe more transit and bike spending won't completely 'solve' traffic, but going by other cities' examples, they should be able to make it less bad.
- kalleboo 9y ago
  I lived in a city that made a conscious effort to retrofit a bike network with many dedicated routes over the past decade and it has paid off with a massive increase in riders (mode share has passed 20%). There was a corresponding decline in people traveling by car, despite the city also expanding the road network by twice the amount at the same time (they didn't reduce funding).

barrkel 9y ago

People have a specific tolerance curve for commute time and traffic. With more and bigger roads, they gradually work and live further away (where land is cheaper and they can have a bigger house) until the traffic reaches the same critical point again. Excess capacity induces demand, attracts it, by enabling people from further away to consume the capacity.

humanrebar 9y ago
> until the traffic reaches the same critical point again Right, but commutable land grows exponentially as roads are improved further from the city center. So, depending on what you value, it's a net win when a twenty minute commute gets you ten miles away instead of five.

stale2002 9y ago

The real solution is to build more housing near where people work, so that people don't HAVE to commute. Oh who am i kidding. Thats politically impossible.

jurip 9y ago
How do you propose achieve that for households with more than one person going to work outside their home? That requires being highly selective when accepting job offers and being willing to move and possibly quit jobs often.
- stale2002 9y ago
  Im suggesting that more houses get built downtown in the city. Not EVERYONE would have to live in the city. A lot are interested, and would move there themselves, and this would cut down on traffic significantly.
  - jurip 9y ago
    Oh, I absolutely agree with building more housing (and office and retail space, etc) and less roads and parking in the city. But that does not eliminate the commute. You have to live in a really small town and/or be very lucky with jobs to not have a noticeable commute. Of course, if you can do that commute on foot, bike or public transit that's better for everyone.

cabalamat 9y ago

> but the alternative is to invest billions into poorly designed public transport Why can't we have well-designed public transport? Edinburgh manages to do this, so I'm sure other cities could if they wanted to. The basic ideas are bus lanes and lots of high-density housing. This would also have advantage of making housing affordable.