Rapid transit in Chile

railway system in the Valparaiso Region, Chile

thumb|200px|Biotrén symbol thumb|200px|A unit of train UT 440 Modelo Concepción, on Chilean station of Hualqui, Región del Biobío. The Biotren () is an at-grade urban commuter rail system that serves a large part of the city of Concepción, Chile, capital of the region of Bío-Bío, also known as Greater Concepción or Concepción Metropolitan Area, both synonyms of "city" according to the urbanistic standards and laws of Chile, of which this city is the second biggest, most populous and important of the country. Biotren connects the boroughs or comunas of Concepción Centro (downtown borough), Talc