>> I believe the argument would be that not creating induced demand will provide market effects to encourage the use of transit
Induced demand is a concept that anti-car people use, but I don't think it makes much sense.
Imagine a library that only has a few copies of some best selling children's books. There's a very long queue to check out those books. Someone might argue that, "We should buy more copies of the best selling children's books".
The induced demand argument in this case would be: "If we buy more copies of those books, the queue wont disappear, since it is so long, but also, if the queue gets shorter, we might have people who don't use the library because of the queue start using it. We would be no better off!".
Of course in this analogy, we realize the fallacy. People are better off because more kids get to read books. Even if the queue stays the same length, we have more throughput, more kids get the benefit.
Now if we translate that to cars, of course, we see the difference. People who write books like "Paved Paradise" or "The High Cost of Free Parking" hate cars. They really do. They hate the suburbs too.
So when they see something that would enable people who don't currently drive cars to drive cars, or for people who live in urban areas to live in suburban areas, they're of course going to be against that.
"Induced demand" is being used here by languagehacker, as it is used by other people who are opposed to private property, as some sort of technical term that supports their case. But that isn't true.
By adding more copies of popular books to libraries, we want to induce demand. We want people to read the books, and we want people who don't currently use libraries to consider using them. The induced demand is not bad. We had a queue, it was too long, we shorten the queue, and by doing so some people who thought the queue was too long will no longer think that. This is good.
What languagehacker is saying, by referring to induced demand, is that, in the opinion of languagehacker cars are bad.
It is as simple as that. It sounds super-scientific when you use terms like "induced demand", but it is not, in fact, super-scientific. It's just a value judgement.
To me, if you build a highway in an area that has high traffic congestion, and after you build the highway, it still has high traffic congestion, it means more people are getting where they want to be. It's called "induced demand".
Induced demand is good. We should have more of it.
This is a flawed analogy and I think there is a false dichotomy by framing skepticism around building more highways as inherently anti-car. I'm going to go out on a limb and say most drivers do not enjoy traffic and most residents near busy roadways do not enjoy the effects of traffic on their neighborhood. The question is what is the best policy approach that manages all people's concerns. For me, the question is how can we get people to live and work in areas where it isn't necessary to inefficiently, and very expensively, move people to and from work.
Since the 1950s, we have optimized for essentially the least efficient form of transit available. It seems completely bonkers to me that in the bay and other high density areas, you have many, many workers, particularly at the low end of the income scale, driving over an hour each way to work. It is an understandable and rational decision for the driver, but crazy to me for society.
> For me, the question is how can we get people to live and work in areas where it isn't necessary to inefficiently, and very expensively, move people to and from work.
I cannot comprehend why more firms aren’t embracing remote work more than they do. It helps alleviate a lot of these traffic challenges and can result in reduced carbon footprints as well as more happy employees. I hope we start considering remote work as a solution to some of these problems more in the future.
I don’t think this analogy is quite correct. Driving on a particular route is not a driver’s objective like reading a particular book is a reader’s objective. The driver’s objective is arriving at a destination. The objective in driving is not a finite resource, but the multiple route options to the objective can be, which differs substantially from a library queue.
Let's consider a library with both a manned librarian and a self checkout, two different queues, same objective. Let's call the self checkout the 'highway' queue and the manned one the 'surface street' queue. Each of which could be expanded to improve throughput (more lanes:more self checkout lanes, more streets:more librarians).
Ultimately the problem with anti-car rhetoric is that it seeks to limit access to the objective because it is "wrong" to use a self checkout lane and people must be forced to check books out in the morally correct manner.
No one (reasonable) has a problem with the library adopting a mobile checkout app, which let's call mass transit. But crippling self checkout to force adoption of the mobile checkout app could be at best described as a 'dark pattern', forcing people to check out books 'the right way' at the cost of overall readership.
I believe there is way too much value judgement placed here.
If you have two checkouts, people will use whichever one is faster (assuming everything else is equal). Make one faster, and people will shift from one line to the other. Though, to make it an even better analogy, make one line shorter, and people will start coming in from off the street rather than switching lines.
A much better example - telecommuting. IF commute is bad, one is strongly incentivized to have some work-from-home days. If the commute time is improved, then that incentive disappears and one would then consider commuting daily.
Induced demand I think is generally all about the idea that when something is painful - people don't do it. Take away that pain point, and people come. I don't begrudge people too much for driving, as an example I'll note I do my errands on a bicycle. As such, I'm strongly incentivized to make many stops and fewer trips. Meanwhile, I've noticed that people in my family will make a car trip errand as soon as the need comes up. "Oh, I need to go to the grocery store." They get back, then realize they also needed to go to the hardware store, drive out again real quick and back when had there been more planning, the two trips could have been combined. Switching to a bike is an extreme example to avoid the excessive/unnecessary trips that are made simply because it is so convenient. If the drive time were tripled, then there might be a behavior shift to group errands together. Why do so though if it takes just a few minutes to make the individual trips? Eventually the cost of the trip is sufficient that a person will start conserving, avoiding that cost (which can be: travelling in off-hours, grouping trips together, not doing a trip altogether, finding a different mode of transport, removing the trip by moving, etc...)
The people who freely use terms like "anti-car" always assume that the car is always the fastest most efficient way of getting anywhere... and then sit stuck in standstill on a 6-10-lane highway
Ah, I think i just realized how to fix the analogy!
The issue is with how many books are checked out a time. If the line is absurdly long, at some point you will make fewer trips to the library to avoid paying the cost of waiting in line. You would check out more books so you would go less frequently. You would be trading storage space at home in exchange for time (not having to wait in line). If the line were infinitely fast, then why not go to the library exactly after you have finished one book to then go get one new book.
If an automated checkout then exists, the line time would be less, making it less expensive to go to the library, which means a person would be willing to increase their trip frequency to the library. Suddenly, you have a line full of people all checking out exactly one book, and returning the next day to do the same thing again (rather than checking out one weeks worth of books, and coming back a week later instead of the next day).
I think that's a fair extension of the analogy, from which I would make two observations:
First is that with frictionless checkout the library's efficiency is maximized (books are only checked out when being read and people's time isn't spent unproductively).
Second is that there is a limit to the demand of the library. A book will be finished before checking out a new one and a person can only read so many books a day. No matter how entertaining there is a fairly hard cap based on a persons need to sleep and reading rate. So a library would only ever need enough automated checkout lanes to match the populations awake time and reading rate before book demand is fully sated.
I really appreciate the dialog! I find your observations interesting.
Though, I do think you might be overemphasizing the number of checkout lanes.
To torture the analogy, let's consider the variables at play:
- how often a person goes to the library
- how many books they check out at a time
- how long they wait to checkout (we can potentially include travel time with this number, and this number is a function of the number of checkout lines)
- how many books can a person use at a given time (can a person read 3 books at a time?)
- how fast a person consumes books
- what is the max number of books that can be transported
- what is the max number of books that can be stored
The variables of "how many times do you go to the library" and "how many books do you get each time", and the cost to do so - "the time to check out", I think are the 3 really interesting variables to demonstrate induced & latent demand. The others are a factor, but we can hold them constant in order to demonstrate the relationship of the other three.
Diving in now - latent demand are people who would rather not read at all rather than spend more time than X waiting to check out. If the time to check out decreases, some people will start making the trip - this is latent demand.
As time to check-out decreases further, some people will start making multiple trips instead of just one - this is induced demand. The people making multiple trips are still checking out the same number of books overall - illustrating there is demand for high frequency and not just an absolute number of books. If all you wanted was 'X' many books, why take more than one trip to get them? The frequency provides flexibility and relieves other costs (carry capacity cost & storage cost).
For example, an expedition to antarctica would be very willing to pay a high cost to have a high carry capacity in order to transport a lot of food (they'll buy a literal boat to carry it) and another high cost to store it (storage space is not free). The expedition is willing to pay these costs because the cost to get more food is so high.
One can also ponder, why not get a lifetime supply of books from a library (ignoring late fees)? To one extent, fitting that many books in your arms and then getting them to your home, and then storing them are costs. Why do that when you could make another trip a week later?
Though, let's say for some reason you knew this was your last ever trip to a library. In this case, you would be highly incentivized to invest in higher carry capacity (eg: rent a truck) and to also invest in storage for the books. (Or, the person would be very incentivized to find alternatives). The really interesting part of induced demand IMO is that typically for existing road resources, we are pretty well into the state where many people would prefer to make more trips than they do today. So when we think about the inverse, as travel costs go down, the incentives to carry more and store more go down - which results in more trips being made. As more trips are made by more people, congestion increases, which creates a balancing effect and a steady state of traffic congestion. Naturally, other factors can break the steady state, the fact there is this counter-balancing force is the (IMO) interesting part of induced demand.
In your example, replacing bulky self-checkout machines (analogous to removing road/surface parking real estate) offers a significant benefit to everyone. More room for what everyone actually wants most: books. The preference for self-checkout machines forces a cost on everyone for the benefit of a few.
And in a lot of cases it does, but the important point is that the argument needs to be framed as you've put it: how do we get everyone what the most of what they want [transportation/books]? Most cost efficiently being implied of course. Being dogmatically "anti" or "pro" anything is looking at the problem wrong.
To the specific example, removing self checkout lanes makes sense if the removal adds more value than the lanes were providing, but not if they are providing more value than their opportunity cost -- perhaps because of woefully understaffed registers and a buggy mobile checkout app the self-checkout machines are responsible for a large portion of checkouts. Which would make them counter productive to remove.
And since the self checkouts exist, there is no interest in paying to have librarians at the register, or drivers on buses; so the self checkout is the excuse for not providing a librarian, which effectively cuts off some users from checking out books at all.
If you are stuck in gridlock in a two hour commute with a soulless car that functions as nothing more than an appliance, then sure, that sounds like my personal version of hell. But for me “The driver’s objective is arriving at a destination.” couldn’t be more of a false statement.
Give me a nice European sports car, a manual transmission, an empty highway and some nice scenery and commuting can be an incredibly relaxing experience. Even when I lived in the Bay Area commuting this way off-peak was awesome. In fact the commute was the highlight of my day.
Same minus the highway (sports car != touring car). Well, Except that I have it: depressed man driving a new MX-5 in the south of France, driving is one of my last joys in life together with food and sleep.
From my personal experience, growing up, people used the term induced demand in a strictly negative sense to describe road expansion plans. Then I lived in cities as an adult where new metro lines opened. The effect is real! Whole neighborhoods would get much more foot traffic after a new station opens. In this case, most people would describe the induced demand as positive.
I agree, "induced demand" is a word phrase to rally behind.
The argument must be (and, I believe, is) that induced demand for buses and trains is far cheaper to a society than induced demand for cars. Adding a train car at a peak time serves a lot more people than adding a highway lane at a peak time.
I'm actually curious to compare them.
Apparently, 100 people is a reasonable capacity for a train car (200 is possible for BART at rush hour). A lane of 100 single-occupancy cars in a traffic jam is about a third of a mile. So, an extra car lane a mile long is about an extra half a train, give it take.
> So, an extra car lane a mile long is about an extra half a train, give it take.
The problem with this math is the last mile.
With a road network you have highways with multiple lanes and a lot of traffic, and those branch out into streets with fewer lanes but more destinations.
You can run a train next to the highway and it will achieve much more throughput, but as soon as you get to the offramp, what now? Those 100 passengers all have different destinations that fork off in every direction. You can't run 100 train cars one for each passenger, that's even worse than the road cars. But you also can't just dump them all right there, miles away from where they want to be.
The reason this works in NYC is the density. You can actually get 100 people who are all going to the same place at the same time. Which is also the only way to make it work anywhere else: Build higher density housing. It cannot work in the suburbs because there isn't enough density to run high-occupancy mass transit at a viable frequency.
Whereas in that environment having the occasional four or eight lane highway increases carrying capacity along more than its own length. The single-lane surface streets that branch off in every direction have a vast amount of otherwise unused carrying capacity, which a highway lane unlocks by connecting low-density destinations together. And which you can't unlock with mass transit because those destinations don't have the density for mass transit, even if the path directly parallel to the highway does.
The problem isn't cars or highways, it's zoning density restrictions.
These are all good points. High-density housing makes trains easier. Conversely, trains induce demand for high-density housing near the stations. There are many other considerations that need to be taken into consideration to make trains useful: frequency, right-of-way on road crossings (often a problem for light rail), right-of-way vs cargo trains (long-distance trains in the US), ...
> The single-lane surface streets that branch off in every direction have a vast amount of otherwise unused carrying capacity, which a highway lane unlocks by connecting low-density destinations together. And which you can't unlock with mass transit because those destinations don't have the density for mass transit, even if the path directly parallel to the highway does.
In a lot of suburbia, there are large parking lots near train stations. In theory, your point is a great advertisement for this setup. In practice, I never lived in a place where driving to the train station was convenient, but it's quite possible that is an accident. For one, parking lots have to be truly large to fit the number of people that would fit in a train car.
> Conversely, trains induce demand for high-density housing near the stations.
The primary existing problem is that high-density housing is prohibited through zoning, or made prohibitively expensive through other regulatory rules. It doesn't matter how much demand you generate if increasing supply is constrained by law. Whereas if you could fix the zoning and building codes then you wouldn't need to induce demand because demand is already there -- it's why housing is so expensive.
> There are many other considerations that need to be taken into consideration to make trains useful: frequency, right-of-way on road crossings (often a problem for light rail)
These are all density again. You get frequency by having enough passengers to fill the transit car on that interval, which you get from higher density. There is no point in sending a bus to carry one person to one house, it might as well be a car.
This is also why right of way and bus lanes are the wrong way to think about it. If you don't have enough density you're going to lose regardless and all the bus lane is going to do is make the traffic worse, because people can't take the bus if it doesn't go where they're going when they're going there and then you're just wasting a lane. Whereas if you do have the density then you still don't build a bus lane because instead you build a subway.
> In a lot of suburbia, there are large parking lots near train stations. In theory, your point is a great advertisement for this setup.
That's trying to have it both ways. If you have to drive to the train station then you have to buy a car and insure it and unless the parking at the train station is free you're now paying for parking. At this point people start wondering why they're hoofing it up to the train platform and paying for transit tickets and waiting for the train instead of just driving the rest of the way to their destination.
To fix this you need more people to live within walking distance of mass transit. Which is to say, you need to build higher density housing or allow mixed zoning so people can live closer to where they work.
>At this point people start wondering why they're hoofing it up to the train platform and paying for transit tickets and waiting for the train instead of just driving the rest of the way to their destination.
Usually, it's because
1) the highway to their destination in the city center has too much traffic, and the train is faster, and
2) there's no parking at their destination, and no place to build it at any kind of affordable price.
Just look at Washington DC: tons of people commute by car to suburban train stations, pay a monthly fee to park in the big parking garages there, and then commute the rest of the way into the city center by train to work in government offices.
You can think of it in terms of simpler concept: "giving people free stuff causes more people to take free stuff".
Cars and infrastructure for them is heavily subsidized so building more if it (giving free stuff away) induces more people to use it.
As car infrastructure has a cost which car drivers don't cover building more if it is very expensive for everyone else that's why we shouldn't want more if it.
i think the point of "induced demand" is that you sometimes can't really fix -- specifically -- traffic or parking congestion problems by building more. if you widen the roads, in many cases it won't make your commute any quicker. if you add more parking spots downtown, more people will drive downtown.
it's not that there's no benefit to the wider road or parking spots, just that the benefit people really care about -- less traffic and quicker trips, less time searching for a parking spot -- often fails to materialize.
That downtown is now a concrete hellscape instead of a pleasant place to be. Your solution ensures that always happens, overall people prefer less infrastructure built for cars, but if it is there of course they will use it.
You say NYC and Chicago has enough highways to fill demand so there is no congestion? I am fairly certain that isn't true, I've read so much about congestion problems in NYC at least. Adding enough roads to fill all demand leads to concrete hellscapes, that was the point, the guy I responded to thought it was reasonable to add roads until all demand was satisfied.
No one is saying no congestion. The idea of highway expansion is to allow more people to travel while keeping congestion about constant. NYC and Chicago's highways allow the massive suburban areas and the tens of millions that live in them to semi conveniently go to the city. To do that with trains would require driving to a commuter rail station and then transferring to the metro to get where you want to go. Suburbanites just wouldnt go to the city in that case unless the destination is easily accessible on the commuter rail
Chicago and NYC have huge commuter rail networks that accomplish exactly what you’re claiming is impractical.
The Metra commuter rail in Chicago handles over 2.5 million trips per month.
59 percent of the people who commute to Manhattan do so via public transit. People commute to work to Manhattan from Connecticut and New Jersey by train.
Penn Station is the busiest transportation facility in the Western hemisphere, serving 600,000 passengers a day, primarily commuter rail and regional rail. And that’s just one station.
One subway tunnel with two tracks is equivalent to something like a 15 lane highway in passenger throughput. That’s where highway expansion truly falls apart: it only really scales up to a small to mid-sized cities before the land waste becomes a burden.
A lot of urban highways have no way to add lanes because there is no more physical space, or you have to destroy the actual destinations that the highway is supposed to serve to expand it.
I will also add that there are a decent amount of suburbs with walkable downtowns along those NYC and Chicago (and Boston!) commuter rail networks where you can buy a condo, rent an apartment, or even a buy a single family home within walking or biking distance of commuters rail and go downtown. In addition, suburban bus lines that feed people into commuter rail stops also exist. So it’s not all park and rides.
And park and rides still help spread traffic across the metro area highway network instead of sending all traffic into to a handful of highways going downtown. If I drive to my town’s commuter rail stop my car is probably not even getting on a highway.
Commuter rail only works if you want to go within a mile of one of the stations. No one wants to take the commuter rail and then get on another train. The people who use commuter rail in Chicago at least all also have a car that they use to get to the city whenever they’re doing anything else since the train only goes to the business area
I think that detractors of transit believe that eliminating cars is the goal like it’s this black and white thing. It’s either 100% cars or 0% cars. “If I can’t do 100% of every possible trip on transit, it’s not a good investment.”
But the reality is that reducing car trips is really helpful to congestion and traffic for everyone, and having alternative options can make a lot of sense to a lot of people if they’re planned well.
If I take all my daily commutes in with the Metra but then my weekend trip to the city outside the business center is in a car, I still reduced my dependency on my car by huge percentage. That means more of my miles are being spent on safer, more energy efficient, less costly mass transit.
And anyway, you’re not really correct here in the first place. Chicago commuter rail stations downtown have easy connectivity to the L and numerous buses.
You just brazenly claim that nobody wants to transfer but it happens all the time.
Yes, it can take longer than driving…except when it doesn’t, because Chicago has two or three of the nation’s slowest highways. Metra plus a transfer is often a trivial difference in travel time, plus on the Metra you can relax, use the bathroom, and even legally drink a beer if you wish.
Many trips using the L plus Metra transfer are pretty competitive to drive times. Obviously it doesn’t work for every trip but doing a Metra ride plus a $10 Taxi ride will beat parking costs, plus you’re not operating and maintaining a personal vehicle.
Finally, for those who can’t drive at all or have difficulty doing so, having an option that’s slower or less convenient than driving is still a godsend. Being able to get somewhere via transit in 2 hours will beat a 1 hour car ride when the alternative is not taking the trip at all because you’re elderly or disabled and can’t drive yourself. If your car got totaled and you can’t afford a new one having a transit option solved the catch 22 of needing a job to pay for a car and needing a car to get to your job.
I’ve lived in Chicago my whole life and have never heard of anyone transferring to cta after taking the metra. Not saying it doesn’t happen, but it’s not scalable solution that people will buy into. The vast majority of people will just drive in that case
I did it every day getting to Ignatius from Beverly, and again getting to my office in South Loop when I lived in Evanston. One advantage the Metra often has is better parking, so even if I could end-to-end take CTA, I might park and ride a scheduled Metra instead. (Doesn't matter anymore, I live a short walk from the Green Line).
As an example, there are 12 different bus lines that are directly adjacent to Millennium Station. You barely even have to step outside to use them.
Hell, you don’t have to step outside at all to transfer from the blue or red line to Millennium station trains.
All loop CTA lines are a 10 minute walk to Union Station and Ogilvie.
You really think with these kind of stats that nobody is transferring?
Not to mention the fact that the Metra runs express trains during rush hour to high population suburbs. You can get from Downer’s Grove to non-downtown neighborhoods like Lincoln Park or Wrigleyville faster than a car during rush hour via express trains + purple line.
The advantage of cars isnt that they are faster than public transit. Its that they are private space and usually a bit more convenient. Arguments about speed will convince no one. The loop buses are doing horribly fyi, the BRT is a complete failure in terms of ridership.
I think the counterpart question to that is, given how space-inefficient cars are, how many actual people do you enable by adding that car capacity, and how does that number compare to even basic public transit options?
If it means way fewer people took alternative means, then perhaps it is not good. Particularly when OP mentioned the original goal was to reduce travel times - which the widening did not.
"it's not that there's no benefit to the wider road or parking spots, just that the benefit people really care about -- less traffic and quicker trips, less time searching for a parking spot -- often fails to materialize."
At some point when you clear out all the actual places to go in order to add parking and make it easy to drive there, people realize there is nothing down there and stop going, at which point you just have what happened to Detroit.
My experience is the opposite. The harder it becomes to visit a locale, the less likely I become to visit it. Eventually I decide it's not worth visiting at all.
That the roads were added based on a request to make it quicker for existing commuters, not to get more commuters there in the same amount of time. And that if you’d used that time, space and money for a dedicated bus lane, a train, a tram or whatever, you might have done better on both adding to the number of people downtown and making it quicker to get there.
the dream is that if i already have to drive downtown, if only there were more parking spots, i could always find one easily instead of driving around searching. but this often won’t happen.
Except that having more car traffic induces more pollution, more casualties, and more time spent unproductively (you can do other things on public transit, or get exercise commuting by bike), whereas more book reading has few downsides.
Investments in infrastructure is investing in huge net benefits for all members of society and the economy in the broadest sense possible. That's why it's been an unparalleled success all over the world to invest in roads for motorized vehicles and invest in electrification. Getting energy and goods to where they need to be as fast as possible is beneficial to all, no matter how you structure your government or economy.
It's not really a benefit to all the ecosystems destroyed by suburban sprawl, or all the people affected by the externalized costs of that economic activity. Unrestricted growth may not be so great of an idea in the long term.
Get harassed by homeless? Or just men in general, if you’re a remotely attractive female (using the broadest term available as it certianly isn’t restricted to what we’d appropriately call “women”).
Do you think public transit is full of drunkards? Its mostly tired people getting to or from work, those doesn't harass a lot of people. When its late and its a lot of drunks on public transit sure, but not on normal commutes. Columns I've read from women getting harassed its mostly about dance floors at clubs, not commute trains, when people aren't drunk they mostly keep their hands to themselves.
That is true everywhere, drunk or affected men are overwhelmingly more likely to harass women than sober men are. Subways here in Europe are full of pretty women, they don't go out of their way to take a car any more than men are, when I count gender on subways there are usually more women than men.
When was the last time you saw women avoid grocery stores because they are afraid of getting harassed? Well used public transit is that level, it isn't something women worry much about compared to many other much larger threats. There is no reason at all for public transit to be worse in terms of harassment than grocery stores are, its just that USA choose to let their public transit become shit.
Grocery stores are different because bums aren’t allowed to sit around there waiting for a woman to come by for them to harass. If they were, I’m confident many would object.
It’s clear that you don’t have much concern for the harassment experienced by those woman columnists you read, so I don’t think there much more I can say here. I imagine if you were to have any direct experience at all with the problem, your position would be different.
That all said: what’s your upside? What do you gain which you consider to be worth these women whom you do not know sacrificing their safety?
That happens because the transit isn't used by enough normal people. The need for security personnel doesn't go up with more normal people, when you have the levels Europe has the crackheads etc gets removed from the trains.
You basically ensures your transit system will remain shitty forever, but that is easily fixable. The more good actors that use it the cheaper fixing it gets per person, you can have people who clean and security remove such bad actors at low cost since so small fraction are causing bad events or pissing where they shouldn't. Good people overwhelmingly outnumber bad people in the real world.
you can reduce the per capita rates of incidents by adding normal people, but even in a city like NYC where most households don't own a car, the subway still has an unacceptable amount of non-violent incidents like the aforementioned one (yeah yeah yeah i know the likelihood of dying on public transit is less per mile than driving)
I agree with the urban planning bias here, especially the idea that you shouldn't build more roads to fight congestion because more people will use them, and thus they'll reach the same saturation point anyways. Mind boggling that this is an accepted principal, and one that is completely disregarded when it comes to any form of transport that isn't a car.
Perhaps a library vs a commercial book store might have worked as a better analogy. The queue theory part of it I think breaks down a lot. Induced demand is not only about queue theory, but also choosing between options.
In short though, induced demand is somewhat simple. If it takes 10 minutes to drive and 30 minutes to take a bus, then I drive. If it takes 30 minutes to drive and 10 minutes to take a bus, then I take the bus. Eventually enough people choose to drive, or take a bus, that that mode becomes congested/inconvenient enough that people start making other choices. In other words, there are some people who avoid highways during rush hour because the traffic jams are bad. If the highway is widened, then they would join the rush hour once again and be part of the traffic jams. Induced demand is about taking away the reason why people avoid something, and thereby doing so they change their behavior to start doing that thing.
Yea but really the choice here is "go somewhere vs stay home", not "car vs bus". Highway expansion leads to more people travelling because bus service is non existent in the vast majority of the country. Of course some people need to go where theyre going, but on the margins more people will go to the city or what not if traffic is lower.
Good points. Yeah, as the cost of travel goes up, people make various decisions: bite-the-bullet, find alternatives, delay, consolidate, and/or go without. As the cost decreases, the incentives to find alternatives, delay or consolidate trips goes down (which means roads are then used for less important reasons and less efficiently - why go to the grocery store once a week if you can go every day in half the travel time?)
I would agree, at some point when all alternatives are equally unattractive (or non-existent), then going without is a more attractive option.
Though, the "consolidate" option is a big one to consider. Rather than going to the city every day, perhaps people could do so every other day for the same benefit. If traffic is bad, then people will go less often (frequency of travel is a function of cost). Thus, in some cases, highway expansion is filled by people that want to go to the grocery store every day rather than going once a week. Meanwhile, those that commute to work, are still going to do so because they have to. If the commute gets too bad, then some people will decide to move.
On the other side of the spectrum, at some point there are so many people that want to go into the city every day - you can't do it with single occupancy vehicles and roads. It's a scaling problem. For example, someone did an analysis of parking decks in Seattle and whether there were not enough of them. They found if there were all filled and everyone then tried to leave - it would take 2 days for all the vehicles to exit the city.
Absolutely agree. I really think the concept of induced demand with highways is misleading. Im not even sure reducing traffic is the point of highway expansion, pretty sure induced demand is literally the goal.
> The induced demand argument in this case would be: "If we buy more copies of those books, the queue wont disappear, since it is so long, but also, if the queue gets shorter, we might have people who don't use the library because of the queue start using it. We would be no better off!".
What you are missing is that every time we widen roads to allow more car throughput we are making every other type of transit and mobility less attractive. Busy streets with big parking lots are unpleasant to walk or bike along, so people just drive to their destinations instead, which makes the street even busier, louder, and smellier starts this cycle all over again. Every time a road is widened or a new parking lot is added the city also becomes less dense, making getting anywhere useful more time consuming. Drivers have to spend longer on the road to get where they want to go, public transit gets more expensive as routes get longer, and walking and biking quickly become too time consuming. There is just a maximum density that cars can support which works totally fine for suburbs but breaks down in denser cities. Personally I think Park and Ride programs are the most reasonable compromise.
People always seem to forget the bus takes advantage of having multiple travel lanes and faster intersection clearance too. City of LA is starting to take advantage of their wide roads and put in bus only lanes, something they could easily do with some paint since the pavement already exists.
Books are not a finite resource? Obviously there is a finite number of trees but there are enough for it not to be a bottleneck. Land on the hand is a finite resource, especially in large, urban cities. There is no way to design a highway or other car infrastructure that will meet the demands of any reasonably sized city without dedicating an unreasonable amount of land to cars. Anyway, Ray explains it better than I could and he agrees that the term is bad: https://youtu.be/za56H2BGamQ
Induced demand is a concept that anti-car people use, but I don't think it makes much sense.
Imagine a library that only has a few copies of some best selling children's books. There's a very long queue to check out those books. Someone might argue that, "We should buy more copies of the best selling children's books".
The induced demand argument in this case would be: "If we buy more copies of those books, the queue wont disappear, since it is so long, but also, if the queue gets shorter, we might have people who don't use the library because of the queue start using it. We would be no better off!".
Of course in this analogy, we realize the fallacy. People are better off because more kids get to read books. Even if the queue stays the same length, we have more throughput, more kids get the benefit.
Now if we translate that to cars, of course, we see the difference. People who write books like "Paved Paradise" or "The High Cost of Free Parking" hate cars. They really do. They hate the suburbs too.
So when they see something that would enable people who don't currently drive cars to drive cars, or for people who live in urban areas to live in suburban areas, they're of course going to be against that.
"Induced demand" is being used here by languagehacker, as it is used by other people who are opposed to private property, as some sort of technical term that supports their case. But that isn't true.
By adding more copies of popular books to libraries, we want to induce demand. We want people to read the books, and we want people who don't currently use libraries to consider using them. The induced demand is not bad. We had a queue, it was too long, we shorten the queue, and by doing so some people who thought the queue was too long will no longer think that. This is good.
What languagehacker is saying, by referring to induced demand, is that, in the opinion of languagehacker cars are bad.
It is as simple as that. It sounds super-scientific when you use terms like "induced demand", but it is not, in fact, super-scientific. It's just a value judgement.
To me, if you build a highway in an area that has high traffic congestion, and after you build the highway, it still has high traffic congestion, it means more people are getting where they want to be. It's called "induced demand".
Induced demand is good. We should have more of it.