Matthew Yglesias  |  slate.com

In 1940, there were 1.5 million people in the city. Twenty years later, it was almost 2.5 million. By 1990 it was close to 3.5 million. Today it’s 3.8 million and still climbing. The larger metropolitan area has ballooned to 13 million residents, leaving Chicago in the dust as America’s second city. And even though the area is built in a sprawling sunbelt format, the geography of surrounding mountains, ocean, and national forests physically constrains L.A.’s growth. Because of that, the average population density throughout the urban area is actually the highest in America even though the core is much less dense than an Eastern city like New York or Boston. The result was legendary traffic jams, combined with a practical inability to widen the arterial freeways that form the backbone of the city’s transportation infrastructure.
The usual response to too much traffic in the United States is to strangle growth. New development would mean more cars would mean more traffic, so cities adopt rules to block new development. {…}