7 Thinking globally . Transportation is an important dimension of our private and public lives. One of the big choices is between private cars and public transit such as buses, trains, and subways. How is the mix of various kinds of passenger transportation different between countries? Why do you think that is the case? If you live in the United States, pick another country for comparison purposes. If you live in another country, you can compare your country to the United States, or to a third country.