As I've started preparing to move to Mexico City, I've been thinking more about the form of cities in the United States, how we got this way and how we might change.
The majority of U.S. cities are designed to move cars. Yes, many older cities have well-known infrastructure like trains and subways but for many decades most of the investment has been in roads and parking. Alternatives like trains, buses, biking and walking are still novel in the grand scheme. Even in Portland, which famously adopted light rail in lieu of building a new freeway, the train is often considered a dangerous, poor-man's way to get to the airport.
However there are four factors that could change the form of urbanization and build support for a new approach to getting around.
First, traffic will get worse. We can't build enough roads and highways because of induced demand.
Second, the cost of driving will keep rising. The high price of gas and the cost of lost time spent in traffic will get more difficult to accept. In my last job I commuted 25 miles each way through Seattle-area traffic -- it's soul-crushing.
Fourth, people are hungry for community. As a result, there are more new communities with a "town square," places where people can walk to stores and restaurants and interact with others. Developers are building places like Mosaic and Reston in Virginia and Issaquah Highlands in Wash. because market research shows people prefer them. This sort of density only makes developing transit easier.
As these four factors gather momentum we'll start recognizing more fundamental changes in our urban transport system. There are others, to be sure, that have helped curtail endless sprawl and are starting to change the way we move around. I'm looking forward to seeing more examples.