Found here: https://twitter.com/CarsRuinedCity/status/1677005785862406144?t=Xolo43mUk4GnegFQE19q3g&s=19
Caption: Photo collage of a beach in Alexandria, Egypt, showing a progression in 3 images:
- Alexandria “Problem” - empty beach + walking street + 6 lane road with medium traffic + dense mid-rise buildings (likely housing)
- Alexandria “Solution” - empty beach (doesn’t seem to matter) + narrower walkway or sidewalk + 10 lane brand new and empty road + tiny sidewalk + the same buildings
- Alexandria “Results” - crowded beach + crowded beach walkway + traffic jam on the 10 lane road
This is one of those arguments that never made sense to me. People like to say that adding lanes just creates more traffic, but what is the proposed mechanism? Does anyone suppose that people who didn’t want to go somewhere suddenly remembered that the highway added more lanes, and then decided to go for a cruise?
It suggests to me that the demand for transit far exceeds capacity, or that this traffic would otherwise have just taken a different route. Probably some of both.
That’s not an argument to just build 15 lane highways everywhere, just that the common form of the supply creates demand argument seems implausible.
Even if the same number of cars are on the road, it is likely that the bottleneck is somewhere else in the city, so adding 20 lanes won’t help the issue anyway.
This like complaining the bathroom is clogged and your solution is to make the showerhead bigger.
The idea behind induced demand is the easier and more convenient/cheaper you make a method of transit the more people will use it. So if you make driving easier by building a super highway people will default to that whole if you build put a rail network that gets peole to where they need to go they’ll take that. Transit being crowded in some ways is a good thing as it shows the route you’ve got is good but could prbsky do with a capacity upgrade. Of course roads being crowded is bad due to massive space inefficiencies and environmental issues.
If you’re looking for a job and you see an opening but it’s going to take you more than an hour each way to get to and from work, doesn’t that make that job less desirable than jobs that are closer by?
Conversely if you’re looking for a new place to live aren’t you going to consider places that are closer to work to be more desirable?
Suddenly there’s road expansion and a house that used to be 2 hours drive away is now 30 minutes drive from you. So you buy the house.
This would all work out great if you were the only one that thought this. But unfortunately there are many many more people that will also get a house or find a job that’s further way, because it’s only a 30 minutes drive now. So now more people are using the highway and that 10 lane highway is clogged, and that commute time starts going back up. But now you have a mortgage now and so you’re stuck. Everyday in your car for more than an hour each way again.
Cars are simply an inefficient way to move a lot of people. A highway expansion only temporarily solves the problem, but when the highways work well, more people use it and those inefficiencies rear their ugly head again.
Induced demand kinda follows the same psychological patterns as the rebound effect. Latter is easier to understand however.
https://en.m.wikipedia.org/wiki/Rebound_effect_(conservation)
That actually does help, I think, for better grasping the concept! Also…
Found that tidbit interesting. The concept of removing the cost savings to insulate efficiency gains against the rebound effect is interesting yet weirdly logical
Here’s an explainer for Induced Demand. You’ll never guess by who: https://www.youtube.com/watch?v=za56H2BGamQ
There are probably a couple mechanisms:
Reduced viability of hyper local services. People drive a longer distance to a central location more than the shorter distance.
Less self-optimization of work-home proximity. People are more likely willing to work further away.
Both can be argued as both a good and bad thing.