Philippine Nautical Highway System

The Philippine Nautical Highway System, also the Road Roll-on/Roll-off Terminal System (RRTS) or simply the RoRo System, is an integrated network of highway and vehicular ferry routes which forms the backbone of a nationwide vehicle transport system in the Philippines. It is a system of roads and ports developed by the Philippine government to connect the major islands of Luzon, the Visayas and Mindanao.

Source: Wikipedia — Philippine Nautical Highway System (CC BY-SA 4.0)