The M-501 is a road in the Spanish region of Madrid. Managed by the Madrid regional government as a primary road in the regional network, it comprises a motorway-grade (autovía) section (from Alcorcón to Navas del Rey) and a two-lane road section (from Navas del Rey to the border with the province of Ávila).
Names
It is named after the old comarcal road C-501 that connected the cities of Alcorcón (near Madrid) and Plasencia (in Extremadura), which was split in three parts and transferred to the relevant autonomous communities. The several dams and reservoirs in the route of the road made the M-501 stuck to the name of Reservoir Road (Sp. Carretera de los Pantanos).