The theory of induced demand says that increasing the amount of roads/lanes available increases the amount of driving - not necessarily of congestion (which implies driving at slower speeds).

In areas that are basically entirely car-dependent, the implication is that more roads encourage more journeys, and that fewer roads result in more journeys not taken. It's unclear why persuading people not to travel is inherently a good thing. Presumably they're going somewhere to see people and do things.

Perhaps building new roads doesn't help them do that any faster, but there are more people getting to do the things that they want.

Adding capacity enables/encourages more sprawl, resulting in more VMT without additional value created.

This sounds like the same sort of silly logic that claims a "road diet" will reduce traffic. Lots of California cities are reducing the number of traffic lanes for no sane reason.

Unfortunately it's hard data and not silly logic. I get the complaint, "we'll make roads worse to get cars to use them less". If it takes 1 minute to drive to the grocery store but 15 minutes to walk, nobody is ever going to walk. If it takes 15 minutes to drive and 15 minutes to walk, though, people will start walking.

The problem with adding lanes to roads is not that people want you to work out instead of sitting in your car. Nobody really cares. The problems is that it doesn't scale, there isn't space to add enough lanes to get everyone into a car. Additional lanes come at the cost of making the road less suitable for walking and biking, further pushing people into their cars unnecessarily. Hence road diets; use expensive urban land for something other than holding slow-moving cars for 3 hours a day.

Car-centric suburbs were an interesting experiment that didn't work out. Unfortunately, half of America owns equity in the failed experiment, so it's going to be a rough couple decades while we adjust to something more sustainable. (Self-driving electric cars aren't going to save them.)

Lol. Not only have they worked out, but virtually every developing country is building their own suburbs. Is traffic an annoying inconvenience, sure. But I (and most people) love the freedom, the space, the variety granted by a car out in the burbs rather than being stuck in a cramped, super-expensive, single-window box in a city somewhere, and relying on public transportation to get anywhere beyond 10 blocks. Been there, done that, for far too long.

Thanks for the explainer. I guess we should do the same thing to the Internet. If it's slower, less people will use it.

Internet capacity isn't scaled by replacing public spaces with toxin-emitting machines, and you can't be hit by one of those machines while crossing the Internet to get to local businesses.

Whether or not you like cars, they're simply not sustainable. It's great that you have one and take advantage of the government subsidies, but it's not a thing that future generations are going to do.

Perhaps we should come up with a replacement before we degrade our infrastructure and reduce the efficiency we had. Also, your statement above basically admits that the infrastructure is being degraded "for the greater good", which is not what your responses above it claim. They claim that reducing traffic capacity results in less usage, but with no mention of the downside.

And your other response above implies that road maintenance is bankrupting suburban cities, but it's entirely possible that those cities are simply not properly prioritizing/managing their spending, which is a common problem in California politics.

The problem is not that they're "nice" or whatever, but that they are financially unsustainable. Property taxes aren't high enough to cover the maintenance on the infrastructure like water mains, sewage treatment, fiber optic Internet, etc. As a result, suburbs are going bankrupt right and left.

You're way off. Detroit (which is not a suburb) went bankrupt, and 62 of the top 75 most populous cities do not have enough money to pay their bills, totalling a massive $333 billion in unfunded debt.

https://www.truthinaccounting.org/library/doclib/Financial-S...

Among most cities that declare, physical infrastructure is usually the least of their problems, it almost always is rooted in public employee pension guarantees that can't be met.

"Unfunded retirement liabilities are the main contributing factor to the $333.5 billion in city-level debt"

The two cities in the worst shape? NYC and Chicago, which are far more urban (and well-serviced by public transportation) than cities like Phoenix, Las Vegas or Anaheim which barely have any downtown urban core and are essentially just large glorified suburbs.

> the San Mateo county page

Propaganda about road engineering written by road engineers. Can you request these "studies"? Any data to share, post-project?

Induced demand is real, that's true. But the degree to which it changes things is highly suspect. Restricting a lane increases congestion in the other lanes. It encourages the far-left lane to make more extreme lane changes (people tend to stay in the fast lane as long as possible, then need to quickly cross 4 lanes to exit). And because it slows normal people down, it increases traffic on non-highways, which has a large number of negative issues: more severe accidents (head-ons and 90-degree impacts are quite rare on divided highways), more idling (more traffic at red lights, which then leads to more drivers having to wait 2 cycles), more pedestrian accidents and more traffic near schools, etc.

Artificial bottlenecks are not an improvement, if the true goal is to increase overall traffic throughput. If the goal is simply to raise revenue for the government, wink wink, then it works great.