The highway system in Puerto Rico is composed of approximately 14,400 kilometers (8,900 mi) of roads in Puerto Rico, maintained by the Puerto Rico Department of Transportation and Public Works (Spanish: Departmento de Transportación y Obras Públicas) or DTOP. The highway system in Puerto Rico is divided into four networks: primary, urban primary, secondary or inter-municipal, and tertiary or local (Spanish: red primaria, red primaria urbana, red secundaria o intermunicipal, and red terciaria o local). Highways may change between networks and retain their same numbers.