5 ms·

induced demand is often (intentionally?) misunderstood as demand being literally insatiable (and by extension, "why bother?"), but really, we're just severly un

induced demand is often (intentionally?) misunderstood as demand being literally insatiable (and by extension, "why bother?"), but really, we're just severly underserving the market, and there are very limited price signals we can rely on to understand the cost and value of a road foot-second (or meter-second). people want more fast, affordable, on-demand, point-to-point private transportation. "induced demand" tells us we're woefully under-providing that demand. we're very far from the desired equilibrium point in nearly every metro area. elon seems to understand that better than a pithy quip might indicate. along with mixed-use-as-default along transportation corridors, i would prefer more underground trains, dedicated busways, and small personal transport infrastructure (for electric bikes, scooters, etc.) in our cities (particularly in LA), but every effort, including the boring company's, that addresses that overwhelming demand helps.

BurningFrog 7y ago
My take is that road access is severely underpriced. If you had to pay for road access, you could easily set the price to where demand meets supply, and all roads would have well flowing traffic 24/7. But of course "induced demand" happens when the price is $0. The same would occur for bread, phones or pianos at that price point.
- fctorial 7y ago
  Roads do have a price, and it does increase with demand. What is the worth of 10 minutes of your time?
  - mc3 7y ago
    Therefore more roads => more cars => same trip times. I could see that people would make decisions to take jobs where they travel by car, or choose to live further away etc. with more tunnels. That could be a good thing or bad, but yes the demand will increase, because people will find new reasons to get about if there is more road to do it on. Let alone business use of roads.
  - MiroF 7y ago
    Do you not see how you're arguing in favor of his/her point?
  - Dylan16807 7y ago
    The problem is that you don't pay for the slowdown you cause to everyone else. You're offloading that cost, so you keep choosing to use the road well beyond the point where traffic should be increasing. To make up for that, we can charge people at the entrance point. But charging people time is basically impossible, so money is used instead.
asdff 7y ago
On paper, when everything is just objects floating in gaseous infinite space, this makes sense. Once you begin to realize that a car takes space, this all falls apart. You can make the 405 100 miles wide to fit everyone across, but you'd loose the entire county in the process. The fact of the matter is that it's absurd to transport people in a dense environment 25'x10' apart, one at a time, all going back and forth to the same exact two places five days a week for 40+ years. Trains let you fit way more people in a given area, people who are already heading the same direction, and therefor offer more space for a city to be a city rather than a place for infrastructure. Until we get to a point where people are able to move easily with high capacity transit, it's irresponsible to waste precious political will to build with the intention of providing low capacity transport for those who can afford a $30k+ car.
- Erlich_Bachman 7y ago
  Aand this is exactly why going 3D (using boring tunnels) instead of 2D is the solution.
- clairity 7y ago
  > "...realize that a car takes space, this all falls apart." that's accounted for in the foot-second metric. by a (very) rough calculation, we'd only need to double road foot-seconds to alleviate most congestion. that's very expensive, since most of these roads would have to go underground or be elevated, but not impossible (elon is trying to do just that for teslas). i'm not advocating we double our roads, however. i'm just refuting the pithy notion that it's impossible to meet the supposedly insatiable demand implied by "induced demand" arguments. but yes, let's build way more public transit and smaller personal transport networks (along with taller, mixed-use buildings)! it's definitely more efficient and can be less expensive and stressful.
rahulnair23 7y ago
I think you've missed the point, going by your second paragraph. How capacity is provisioned from A to B influences how people choose to move and, over the long term, build homes/workplaces. Induced demand does not suggest that supply is less than demand - it implies that demand is "flexible" to meet any supply conditions. There is overwhelming evidence of this at work over 50 years and across continents. As a consequence, the argument is not "why bother?" but rather - "build it in a way that scales". For urban areas, private transport doesn't scale well.
- clairity 7y ago
  > "Induced demand does not suggest that supply is less than demand - it implies that demand is "flexible" to meet any supply conditions." that's the exact interpretation i'm refuting. of course supply is less than demand. that's because the price of using roads is (perceived to be) zero, but the cost of construction on the supply side is high (and increasing, relative to inflation). it's impossible to meet the demand for free when costs are high. my point is that this mispricing is a political and cultural choice, not an economic one explained by "induced demand". by using an economic concept for a non-economic market, we fall prey to misinterpreting and misadvocating. we need to make the price of private transport much more transparent (e.g., real-time pricing) and rein in costs (land prices, legal/regulatory costs) so that we can make better choices in allocating our precious and limited resources (toward more mass transit for example). (real-time pricing should also be progressive so that roads aren't just for rich people.)

BurningFrog 7y ago

My take is that road access is severely underpriced. If you had to pay for road access, you could easily set the price to where demand meets supply, and all roads would have well flowing traffic 24/7. But of course "induced demand" happens when the price is $0. The same would occur for bread, phones or pianos at that price point.

fctorial 7y ago
Roads do have a price, and it does increase with demand. What is the worth of 10 minutes of your time?
- mc3 7y ago
  Therefore more roads => more cars => same trip times. I could see that people would make decisions to take jobs where they travel by car, or choose to live further away etc. with more tunnels. That could be a good thing or bad, but yes the demand will increase, because people will find new reasons to get about if there is more road to do it on. Let alone business use of roads.
- MiroF 7y ago
  Do you not see how you're arguing in favor of his/her point?
- Dylan16807 7y ago
  The problem is that you don't pay for the slowdown you cause to everyone else. You're offloading that cost, so you keep choosing to use the road well beyond the point where traffic should be increasing. To make up for that, we can charge people at the entrance point. But charging people time is basically impossible, so money is used instead.

asdff 7y ago

On paper, when everything is just objects floating in gaseous infinite space, this makes sense. Once you begin to realize that a car takes space, this all falls apart. You can make the 405 100 miles wide to fit everyone across, but you'd loose the entire county in the process. The fact of the matter is that it's absurd to transport people in a dense environment 25'x10' apart, one at a time, all going back and forth to the same exact two places five days a week for 40+ years. Trains let you fit way more people in a given area, people who are already heading the same direction, and therefor offer more space for a city to be a city rather than a place for infrastructure. Until we get to a point where people are able to move easily with high capacity transit, it's irresponsible to waste precious political will to build with the intention of providing low capacity transport for those who can afford a $30k+ car.

Erlich_Bachman 7y ago
Aand this is exactly why going 3D (using boring tunnels) instead of 2D is the solution.
clairity 7y ago
> "...realize that a car takes space, this all falls apart." that's accounted for in the foot-second metric. by a (very) rough calculation, we'd only need to double road foot-seconds to alleviate most congestion. that's very expensive, since most of these roads would have to go underground or be elevated, but not impossible (elon is trying to do just that for teslas). i'm not advocating we double our roads, however. i'm just refuting the pithy notion that it's impossible to meet the supposedly insatiable demand implied by "induced demand" arguments. but yes, let's build way more public transit and smaller personal transport networks (along with taller, mixed-use buildings)! it's definitely more efficient and can be less expensive and stressful.

rahulnair23 7y ago

I think you've missed the point, going by your second paragraph. How capacity is provisioned from A to B influences how people choose to move and, over the long term, build homes/workplaces. Induced demand does not suggest that supply is less than demand - it implies that demand is "flexible" to meet any supply conditions. There is overwhelming evidence of this at work over 50 years and across continents. As a consequence, the argument is not "why bother?" but rather - "build it in a way that scales". For urban areas, private transport doesn't scale well.

clairity 7y ago
> "Induced demand does not suggest that supply is less than demand - it implies that demand is "flexible" to meet any supply conditions." that's the exact interpretation i'm refuting. of course supply is less than demand. that's because the price of using roads is (perceived to be) zero, but the cost of construction on the supply side is high (and increasing, relative to inflation). it's impossible to meet the demand for free when costs are high. my point is that this mispricing is a political and cultural choice, not an economic one explained by "induced demand". by using an economic concept for a non-economic market, we fall prey to misinterpreting and misadvocating. we need to make the price of private transport much more transparent (e.g., real-time pricing) and rein in costs (land prices, legal/regulatory costs) so that we can make better choices in allocating our precious and limited resources (toward more mass transit for example). (real-time pricing should also be progressive so that roads aren't just for rich people.)