Your tour operator will take care of all of your transportation requirements. The majority of the time, this implies buses, but tour groups visiting isolated locations (such as Paekdusan and Mount Chilbo) may utilize Air Koryo’s chartered aircraft. It is not permitted to wander about on your own, and you must be accompanied by a guide at all times.
Most visits to Pyongyang involve a carefully staged one-station ride on the Pyongyang metro, but using any other form of local public transportation is usually impossible. Some trips also include a rail journey from Pyongyang to the border city of Sinuiju, where you may stop for a 1-day tour, but US citizens are not eligible for this option.
It is also feasible to arrange a walk around select districts of Pyongyang with some travel agencies if you are traveling in a small group (Koryo).