37) is a free part of the federal highways corridors (Spanish: los corredores carreteros federales) of Mexico.

[4] The highway runs from Villa de Zaragoza, San Luis Potosí, at its northern point to Playa Azul, Michoacán, located near the Pacific Ocean, at its southern point, near the port city of Lázaro Cárdenas, Michoacán.

14 at Uruapan, Michoacán, and Federal Highway 200 at La Mira, Michoacan.

37 runs in two separate improved segments: the first segment runs from Villa de Zaragoza to San Felipe, Guanajuato.

The second segment runs from Manuel Doblado, Guanajuato, to Playa Azul at Fed. 200.