Thinking about growing up in Los Angeles and going to college in Washington D.C., I know using public transportation to get to school or work is very common. I think Seoul's public transportation system is very convenient and efficient. I learned how to use public transportation very quickly and so have my friends who came from other cities in America where there is less public transportation available.
In Seoul, there are five main methods of transportation: driving a car, taking the bus, taking the subway, taking a taxi and walking. Although people in the city own cars, many people take public transportation because traffic in Seoul during rush hour is inconvenient and frustrating to navigate. You can use the same transportation card, called a T-Money card, to pay for bus, subway and taxi fares. More money can be added to a T-Money card in subway stations and most convenience stores.
I usually take the blue bus when I want to go to church because the church I go to is a little far and the blue buses go farther distances. I take the green buses when I want to go to neighboring regions like Hongdae or Myeongdong because the green bus stops are more localized. The closest bus stop to me is about a five-minute walk away and 16 different buses stop there, which is very convenient. Buses stop at the same bus stop every 5-10 minutes depending on the time of day.