The Strada statale 131 is an Italian state highway 226.0 kilometres (140.4 mi) long in Italy. It is the major road in the region of Sardinia. It is a freeway that connects the towns of Porto Torres and Cagliari via Sassari, Macomer and Oristano. It is considered the "spinal cord" of Sardinia. It is a part of the E25 European route.