2) is a free part of the Mexican federal highway corridors (los corredores carreteros federales) that runs along the U.S. border.

The highway is in two separate improved segments, starting in the west at Tijuana, Baja California, on the Pacific coast and ending in the east in Matamoros, Tamaulipas, on the Gulf of Mexico.

2 has a connection to all official ports of entry into the United States, with the exception of the international bridge between Ojinaga, Chihuahua, and Presidio, Texas, which is between the two highway segments.

The western segment begins in Tijuana, Baja California, and terminates at El Porvenir, Chihuahua, near Ciudad Juárez.

The eastern segment begins at Ciudad Acuña, Coahuila, and continues to the Gulf of Mexico at Playa Bagdad, Tamaulipas, in Matamoros.

The joining of the separate improved segments would not decrease travel time as the route follows the course of the Rio Grande (Río Bravo del Norte) around the Big Bend region of Texas.