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Comment by NikolaeVarius | Hacker News Reader

If the point of adding lanes is to reduce delays, and induced demand prevents that, you have failed in the task.

The point of roads, from the city's perspective, is to support additional transportation, which causes growth of the city.

More transportation means more trade, more services, and better life for all who live near the roads. It might be in the form of easier-to-get deliveries (Amazon goods), or new jobs that have popped up close by, or new housing developments (aka: homes that previously weren't possible due to the time of transportation, but are now possible thanks to sped up transportation times).

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It turns out that "individualism" is a crappy reason to do anything. The individual argument must be made because we live in a democracy, and its impossible to get the people to agree to something unless you sell them a story regarding individualism.

You are moving the goalpost.

The purpose of adding lanes was to REDUCE DELAYS. Not support additional transportation. Your entire post hinges on an incorrect premise

It's not correct that cities look at road throughput with no concern for how long that travel takes. The success criteria that city planners use always includes travel times which are impacted substantially by traffic congestion.

That means you didn't add enough lanes. You need to get ahead of induced demand, otherwise you city isn't meeting the needs of the people who live there. If you don't want to have many places you can reach in a reasonable amount of time can you can move to a rural area. The point of cities is to give people options to reach lots of places quickly. Get busying being a good city.

Note, it can be better to add transit other than lanes of road. Even though I said add lanes, adding lanes is but one possible solution. Good transit may well be better. Figure out how to make your city serve the people who want to get around.

> You need to get ahead of induced demand, otherwise you city isn't meeting the needs of the people who live there.

Well, there's an annoying edge case that must be considered as well. In some cases, "induced demand" is "stealing demand from somewhere else".

Lets say you have Town Foo and Town Bar. If you build a highway to Foo, all the additional traffic might be "stealing" traffic from Town Bar and benefiting Town Foo. Especially if people emigrate out of Town Bar for closer housing to Town Foo, you didn't really improve the lives of anyone. You just caused everyone to migrate over.

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Ideally, you want to build highways / roads / transportation in ways that benefits people, and causes the least inconvenience to other towns.

Only if town bar isn't a place people want to be. I call it a good thing is bad towns die.

Well sadly, roads have a bad habit of being confined by physical time and space and cannot just be arbitrarily widened.

You can go up and down though.

Again, I'm not making a value judgement here. Transit is a valid option that could be better

Up is expensive and rather unpleasant for those walking nearby on the surface. Down is even more expensive.

Don't forget that no matter how many lanes you add to a highway heading into a city, eventually that highway ends up... in the city. Too many cars in a city makes for a loud and dangerous-to-navigate environment for those who live there.

The point of adding lanes is not to improve commutes. It's to improve thoroughput. If you add more lanes, and traffic moves at the exact same speed as it did before, guess what that's a win. Your throughput is now higher, more vehicles are moving per hour, and that ultimately means fewer trucks clogging up the port across town (or across the country).

If induced demand is going to negate the improvements from adding capacity, then why not just reduce capacity to one lane? Or less?

The point of adding lanes is to increase throughput.

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