Why would we do nothing different?
The Star Tribune reports on a recent local "scare forecast" (notice the "scare quotes") that local agencies have put out about how traffic will get remorselessly worse in: Rush hour traffic: Get ready to crawl. I get quoted saying it won't be so bad. Clearly MnDOT won't be spending as much on new construction, but there is no evidence individuals will travel as much, in the peak, in 20 years, as they do now, (peak travel, etc.)
The claim is the region is growing, which might be true, but I suspect optimism here (as we approach a fifth full month with snow on the ground).
If congestion gets worse, you would expect people to adapt. Cars will be better (and hopefully autonomous), increasing capacity (both in terms of closer spacing and narrower lanes). Roads will be priced, decreasing peak demand. Telecommunications technology will get better, finally enabling travel-substitution for a large share of the population. If we do nothing different, things will be worse. Knowing that, why would we do nothing different?