this post was submitted on 09 May 2024
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People will talk about induced demand and all that. But those people really just want to be able to get around. The fact that they just don't because the traffic is so bad doesn't mean you shouldn't add more lanes. It means you should add a lot more. Same with the one lane at a time approach. The fact that it didn't work does mean you are doing something wrong, but it maybe that you need to add 5 lanes at a time, not one. Now I'm not saying they should actually do that, just that the arguments against are BS.
A comprehensive public transit system, well maintained and well patrolled is what LA really needs. I am talking Paris metro on steroids. And it is going to cost in the trillions. But it isn't getting any cheaper by waiting.
There are other reasons.
Adding, say, a sixth lane doesn't increase capacity as much as adding a 2nd lane, because traffic jams are generally because of interactions. It's very rarely the straight road that has a capacity problem. Adding a sixth lane adds capacity, but also creates more interactions.
Also, car lanes have a shit capacity, which goes down massively when it's busy. Like you said, mass transit is vastly superior, but even a dedicated bus lane would help. In contested traffic, a car lane transports less than a single bus per hour.
Yeah, the interactions suck. But if dealt with earlier, they could have been mitigated. Same way mass transit does. Express trains. Have a highway over a highway that goes to a specific place. If you stack enough of those, people get on the one they need and go straight to where they need to get. Not realistic though unless planned in advance.
That's the whole thing about induced demand though: People want to get somewhere and believe it or not, not everyone does so by car. But if you decide to add more lanes it temporarily improves traffic leading to those people that didn't take a car in the past or lived somewhere else because they knew traffic would be horrible if they moved, to actually commute by car now / go forth with their plan to move, increasing the amount of traffic again until it's as bad if not even worse than before. Cars don't scale. Cars aren't for mass transport and shouldnt be used for that. A city with a highway like in the picture really needs a transit system/a better one and fever lanes
See you are missing the point. The demand isn't induced, it was always there. They wanted to move and use thier car, but traffic was too bad. My complaint is with the BS argument that the extra lane caused demand to materialize out of no where. It was always there, just unserved.
Did they though? To some extent, yes. But most people just want to get places and will take whichever mode makes the most sense for that journey, and what a city invests in will make that mode make more sense for more journeys. There is also a portion of journeys that just won't happen if they are too difficult.
Distinction without a difference to the point. The demand was always there. It was never induced.
Beyond the fact that adding five more lanes would still leave you with a horribly inefficient transport system, you also ignore that externalities that you are exacerbating by doing so. You're displacing thousands more people, worsening the division of communities, creating a lot of noise and air pollution, increasing car dependency etc
My last paragraph agrees with you.
Your last paragraph is tangential to what I said. It doesn't disagree because it says something different. It's also oversimplified in some ways and just wrong in others.
I always feel like these induced demand arguments are suggesting that adding more lanes means the same number of people are just choosing to do more driving. Maybe, as you add more lanes you create the infrastructure for a city to grow, and it adds more people which then fill up the new lanes. People aren't just going out and buying a new car or rolling an existing car out of the driveway that they were previously not using because a new lane is built. These are net new drivers, who would not be in that city if the infrastructure for them hadn't been built.
Exactly, thank you. If you build a 6-lane highway in Montana it's not going to magically fill up with traffic, thus one can conclude that context is missing from the Reddit-tier explanation of induced demand or that the entire idea of induced demand is wrong.
Induced demand actually means that more people drive now because the people that didn't drive in the past / lived somewhere else because it was less convenient because of the traffic to commute by car or live somewhere else where they would have needed a car now decide to commute by car / actually move (yeah that also something we have observed) because the widening temporarily improved traffic. In the end traffic ends up the same if not worse. Induced demand isn't something the Internet has come up with. It's actually a real thing that has been studied and researched. We know it exists. It functions on the basic principle of: If you improve something and make it more convenient to use that something, more people will actually use it.
But the demand was always there. They wanted to move, they just didn't. So the lane didn't induce it. The choice of that word was intentional. It was to argue against more lanes. It is really unserved demand that they just ignored originally.
trouble is more lanes are useless if so many people are lane hogs.
Too many times have i been stuck behind someone doing 60 in an overtaking lane with with nothing in the slow lane
People aren't hitting 60 in LA during rush hour...
People on here love to shit on Houston's massive expansion of I-10 as a failure.
It worked great for years, but the population continued to grow. Having 5 fewer lanes on each side would just make things worse or increase sprawl by pushing people further out to thin the traffic. They ain't gonna mass-adopt bicycles in a city where the heat index is 115° + for months at a time
But that's the thing about induced demand. Of course widening a road temporarily improves traffic. But only temporary. That temporary improved leads to more people deciding to drive a car when they didn't in the past or even having different moving options in mind now which they didn't because if traffic. In the end traffic ends up the same if not worse than before. That's not something the Internet came up with. It's been studied and researched for years. It works on the simple principle of: If you make something more convenient to use, more people will use it. Cars just don't scale. They can't do mass transport and aren't meant for that. You need to make a city walkable and have a proper public transport system otherwise you will only ever lose even more money on car infrastructure while continuing to worsen traffic, heating up the city because of the sealed surfaces, making the city less desirable to actually exist in and worsening it's economy. Build the city properly and people will actually choose a different option. No matter the climate in that city. Especially because heat is only worse with massive amounts of car infrastructure because they usually result in less green spaces and trees which provide shade and a cooling effect in the city.
What creates demand on I-10 in Houston is population growth. People haven't swapped from taking the bus to using a car. Houston leads the country in population growth. You add a couple million people to a me triplex and the infrastructure needs upgrading.
And trying to make people swap to a car by making traffic shitty works in some areas, but major cities that were largely developed after the invention of the car are almost impossible to retrofit for public transit. It's even worse in hot climates where the city was largely developed after air conditioning. My commute in a different Texas metroplex has gone from 45 minutes to 2 hours because of traffic, but between housing costs in the city and the lack of infrastructure to build transit I still drive every day and can't consider anything else.
Houston spends bonkers money on its light rail that nobody uses between May and October because last-mile transit is a problem in a city where you'll sweat through your clothes waiting 10 minutes at a bus stop. The office would smell like a gym if people used it.
I work in municipal development, and it's a rite of passage for planners to come in from out of state all excited to kill parking standards and shut down roads to make downtown pedestrian-only. Then they spend their first summer here and realize that when you have months of uninterrupted 100°+ days that you can't just wish away the necessity of door to door transportation.
And the widest parts of I-10 are not the everyday choke points. Other parts of the system are the worst offenders on traffic.