So while I don't doubt that this relationship ('traffic increases to fill the available road space') is true for some conditions, it's not a universal law. The real question is finding out where it starts to break down. Maybe there is some merit to building a super wide highway ;)
Actual number of cars should be lower after the highway is built because construction would require removing houses to make room for it.
I'm sure this is in many cases true, but there is a danger in mistaking the metrics for the goals here. If people drive less, it makes the numbers look better, but people staying at home saying "it's impossible to get anywhere this time of day" is hardly the mark of an effective transportation system.
And if the problem you are solving is "get more people where they are going" all of a sudden highways no longer look like a cost-effective solution at all, and public transportation looks _a lot_ better. A lot of highway expansion gets justified by the claim that it will reduce congestion, despite a huge amount of empirical evidence and theoretical justifications (e.g. TFA) that it does not.
EDIT: fixed PSNW -> PNW
- fuel being cheap,
- time spent driving having a low value,
- zoning that discourages high-density development, and
- overhead costs of buying and selling homes high enough to discourage moving nearer to work.
Instead of these hyphenated iron laws of transportation demand that no one has ever heard of that all say the same thing, the article of "induced demand" ought to suffice, and these formulations, if they exist original sources at all, ought to become references in that article's footnotes.
First why is granularity at the level of induced demand ok, but not the Lewis-Mogridge position? Why not put it all in the supply and demand page?
Second, if I come across the Lewis-Mogridge position, and Google it not knowing what it is, should I expect, and prefer, a link to a research paper, a broad wikipedia page most of which is irrelevant to my question, or an actual page that answers my question?
Personally I'm a wikipedia maximalist. Record everything, keep it around for posterity. If in 50 years they want to know what we thought about X, they can find out, and we today can reliably find out about X too.
The cost of this page us virtually zero, why not?