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. The 919-kilometer (571 mi) nautical highway was opened to the public on April 12, 2003 as the Strong Republic Nautical Highway (SRNH).