Mexican Federal Highway 40, also called the Carretera Interoceánica (Interoceanic Highway) is a road beginning at Reynosa, Tamaulipas, just west of the Port of Brownsville, Texas, and ending at Mexican Federal Highway 15 in Villa Unión, Sinaloa, near Mazatlán and the Pacific coast. It is called Interoceanic as, once finished, the cities of Matamoros, Tamaulipas, on the Gulf of Mexico and Mazatlán on the Pacific Ocean will be linked.
It passes through Monterrey, Nuevo León; Saltillo, Coahuila; Torreón; Gómez Palacio and Durango City. The Monterrey to Durango City section is a four-lane divided highway. The rest of the road is a two-lane undivided road. Parallel to this highway, in some sections, runs Federal Highway 40D, a four-lane restricted access toll road.
The Cadereyta Jiménez massacre occurred on 13 May 2012 along the road outside the city of Monterrey.
From Reynosa, Tamaulipas, to La Junta, Nuevo León, the road is a 4-lane divided unrestricted access road. At La Junta the highway is divided into Highway 40 and Highway 40D. Highway 40 continues as a 2-lane undivided road, passing through several small towns including:Peña Blanca, Nuevo León
General Bravo, Nuevo León
China, Nuevo León
Cadereyta Jiménez, Nuevo León
From Monterrey, Nuevo León, to Saltillo, Coahuila, Highway 40 is a 4-lane divided unrestricted access road. The highway crosses the northern end of the Sierra Madre Oriental that divides Coahuila and Nuevo León.
From Saltillo the road continues west as a 4-lane unrestricted access road. After the town of El Mesón, the road splits into a 4-lane toll Road 40D and a 2-lane undivided unrestricted Highway 40. Both roads merge again in the town of 28 de Agosto and begin another section of 4-lane divided unrestricted highway. A few kilometers ahead is the road junction south to Parras de la Fuente. At La Cuchilla the road splits again into 40 and 40D. From there, one may take Federal Highway 30 to San Pedro, which eventually becomes a 4-lane divided unrestricted road and leads directly to northern Torreón. At the city of Matamoros, Highways 40 and 40D merge again into a 4-lane divided unrestricted highway until one reaches Torreón.
This section is the east-west section across the central Mexican Plateau.
Torreon, Coahuila, and Gómez Palacio, Durango, form a metro area. At Gómez Palacio, Highway 40 merges with Highway 49 that comes from the north. At Gómez Palacio one can choose between 40-49 and 40D-49D; both roads are 4-lane divided until the first toll booth.
At Gómez Palacio one can choose between the toll road and the unrestricted road. At Cuencamé, Durango, the roads splits: Highway 49 continues south to Zacatecas and Mexico City, and Highway 40 continues west to Durango.
This section of the highway is narrow with lots of curves and has recently been replaced with the new highway 40D. The old Highway 40 can take up to 8 hours to travel, while Highway 40D should only take 3 hours. During the winter months there is the added danger of ice. When going eastbound, Mazatlán to Durango, after reaching the top of the Sierra Madre Occidental, Highway 40 becomes more linear, and it goes through the towns of La Ciudad, El Salto, and El Soldado. It continues linear up to a point around 30 kilometers from Durango, and it goes downhill with a lot of curves again. In all the downhill sections, the use of engine brake is advised.
The construction of the new highway between Durango and Mazatlán will shorten time between the two cities by as much as 6 hours. The highway will pass under and over the Sierra Madre Occidental through 63 new tunnels and 115 new bridges. The most important is the Baluarte Bridge (finished in 2012), which is now the highest bridge in North America at 390 meters. The bridge is located at the border between Sinaloa and Durango states formed by the Baluarte River. The clearance from the river bottom is over 400 m (1,300 ft), and at over 1,100 m (3,600 ft) long it is the highest suspension bridge in the world. The route from Mazatlan to Durango has 115 bridges, eight over 270 m (890 ft) high, and 63 tunnels nearly 18 km (11 mi) long in total.
Security is expected to be greatly enhanced in this region, due to quicker access and mobility of the military. It was inaugurated by President Enrique Peña Nieto on October 17, 2013, and has been fully operational since then. The time to travel from Durango City to Mazatlan takes slightly under two and one-half hours.