the automobile
Except for a few major cities, the main transportation is automotive. You can find bus routes, railway, airline, subway, taxi ect that will bring you anywhere as there is no shortage of options most anywhere you go.
The main transportation is the automobile. With the exception of New York, Washington, Chicago, and Boston, only poor people and foreigners on vacation use public transit.
That would really depend on the area where you would living. There are subway and city buses. And then there are shuttle buses. Rapid transit trains. All of them are of reasonable cost for monthly pass.