If there were a Paris or Barcelona in the U.S, tons of people would move there. Cost of living in this "Paris" or "Barcelona" would skyrocket and you'd see the transit system hit the max and cost of housing skyrocket. There are just fewer cities in the United States with good transit systems, low-crime, high quality of life and urban amenities. This hypothetical city would go through similar growing pains as NYC and San Francisco have gone through with decent transit systems that just can't keep up with population growth.

The logical conclusion of this article is that a higher entity, likely the federal or state government, needs to step in and provide resources to help these mid-tier cities with their growing pains, assuming the optimal scenario is not another metro area with suburban sprawl and lots of traffic. As it stands now, it's unlikely this will change until the system gets much worse due to the high cost of intervention. It costs $1 billion for just one mile of rail in Los Angeles and New York City, and Paris has 133 miles of rail to support a population of only 2 million.