Taxis are plentiful and cheap. Some are equipped with a translating service that helps you communicate with the driver.
Buses run from 5:30 a.m. to midnight. Stops are posted electronically in English and announced by recorded message in English.
Visitors who are new to Seoul should probably not drive there. If you must rent a car, you will need to be at least 21 years old and have an international driver's permit.
Seoul's modern, efficient subway system is the fastest and cheapest way to get around. It runs from 5:30 a.m. to midnight.
Bicycles are rare in the city, though there are some bicycle paths near the Han River and other attractions.