Go where the MRT doesn't reach yet.
The Taipei Bus system is a network of privately operated bus companies working in cooperation with the city governments to provide comprehensive service to all areas of the city. While most passengers will choose the MRT for transportation needs, sometimes the MRT doesn't reach a particular destination, and bus service will be necessary.
There are many lines which operate in all directions crossing the city. Most lines will eventually pass an MRT station.
The most popular lines are those running shuttle services between MRT stations and remote communities or areas that don't have MRT service such as mountains.
Riding the Taipei Bus is not as easy as the MRT. While the MRT has complete English service, it is not guaranteed that all buses will have comprehensive English service. While station names are legally supposed to be provided in English, in practice this is not guaranteed, nor will bus drivers be able to communicate in English, unlike MRT employees.
Rides on the Taipei Bus can be accomplished by paying NT$15 in cash per line section, or more easily, by swiping an Easycard or iPass card twice, once when boarding, and once when alighting the bus. The system will automatically calculate the fare for you.