Since the 1980s, Texas A&M University’s Texas Transportation Institute (TTI) has periodically trotted out updated versions of its Urban Mobility Report, which purports to estimate the dollar cost of urban traffic congestion. The report has been repeatedly debunked, but after a four-year hiatus, it’s back, and it’s making the same false claims based on the same discredited premises.

There’s so much wrong with this report that it’s impossible to fit all the criticisms into a single article. But to quickly summarize the lengthy case against the Urban Mobility Report (UMR), we’ve pulled together a kind of CliffsNotes version, skimmable by people who just want a quick overview of the issues, with links to other resources where they can go deeper.

Here, then, are the top twenty reasons to be skeptical of the Urban Mobility Report:

1. TTI claims that the UMR proves traffic is worse than at any time since 1982—but major methodological changes make these invalid.

2. The UMR, in the words of Victoria Transportation Policy Institute executive director Todd Litman, “ignores basic research principles,” including failing to allow other experts to review its data and findings — the sort of “peer review” that is foundational to social science investigations. The 2019 iteration of the report simply ignores the multiple, widely published critiques of its methodology.

3. As the Eno Foundation’s Rob Puentes notes, the UMR measures mobility, not access. That is, cities get high scores if you can drive really fast — not if you can actually reach jobs or amenities in less time.

4. In many cases, the UMR counts an inability to drive faster than the speed limit as “congestion.” The 2019 report counts any reduction of freeway speeds from 65 miles per hour as “time lost to congestion” even if the posted speed limit is 50 or 55 miles per hour. It’s indefensible that this report treats the inability to break the law as a “cost,” especially when speeding is proven to be a major contributor to road fatalities.

5. The report fails to acknowledge that there’s simply no feasible way to build enough road capacity that all vehicles could travel at free flow speeds (often in excess of speed limits) every hour of the day. The cost of building such capacity would be vastly greater than the supposed “cost” of congestion, meaning that in reality the net cost of congestion is zero (or less).

6. The UMR completely ignores the effects of induced demand: building more road capacity stimulates more sprawling development patterns, and more driving, which actually aggravate congestion and lead to more pollution and higher costs for the public and commuters. The phenomenon of induced demand is now so well-established that its referred to as “the fundamental law of road congestion.”

7. Practical experience with capacity expansion has shown that wider roads don’t reduce congestion. In TTI’s own backyard, the multiple widenings of Houston’s massive 23-lane Katy Freeway have only produced more traffic and even slower travel times. There’s simply no evidence than more capacity reduces congestion.

8. It’s remarkable that as traffic engineers, the authors of the UMR ignore the fact that freeways carry the highest amount of traffic at speeds of about 45 miles per hour. (At higher speeds, car spacing increases and roads can carry fewer cars). Building enough capacity to allow 55 or 65 mile per hour speeds is vastly more expensive and less efficient than designing to accommodate a speed that maximizes throughput. This is advocacy for waste.

9. The UMR has no solution for congestion because it lacks a credible explanation as to why congestion exists in the first place. While the report acknowledges (p. 12) the “imbalance” between demand and supply, it fails to consider that the fact that we charge a zero price for road use means that demand inevitably overwhelms supply in urban areas. As I’ve illustrated with the Ben and Jerry’s seminar on transportation economics, a zero price for a valuable commodity is the cause of congestion and queueing.

10. The UMR claims that congestion got worse every year between 2009 and 2014, but contemporaneously published data from Inrix (supposedly the source of the UMR estimates)—show that nationally congestion declined by about 30 percent during these years, due largely to a decline in vehicle miles traveled. Inrix has disappeared this data from its servers, and the Texas Transportation Institute has never explained the discrepancy.