When the US exited the Philippines after World War II many jeeps were either sold or given to filipinos.  These vehicles were modified by adding metal roofs, long beds, bench seats and bright colors and then used for public transportation.  You see them everywhere in Manilla.  Similar to city buses you enter and exit at various stops and pay for the distance that you travel.  In addition to driving the drivers keep up with where each person  gets on and off to calculate the fare.