National Route 7 (full name in Spanish: Ruta Nacional 7 Carretera Libertador General San Martín) is a road in Argentina. It crosses the country from east to west, from the capital (Buenos Aires) to the border with Chile, thus linking the Atlantic coast with the Andes, crossing the provinces of Buenos Aires, Santa Fe, Córdoba, San Luis and Mendoza. It has a total length of , of which (30%) are freeways.

National Route 7 is a branch of the Pan-American Highway, continuing into Chile under the name of Route CH-60.

History

The origins of this route go back to the Western Camino Real, which was used since the colonial era. The Western Camino Real started at Buenos Aires, ran through San Luis and Mendoza, and ended at Santiago de Chile. The road decreased in importance with the introduction of railways at the end of the 19th century.

New settlements sprang up along the route, that were only served by the railway.

With the improvements in automotive travel, the National Congress created the National Highway Directorate in 1932. In 1935, that organisation started work on a new road parallel to a railroad operated by Buenos Aires and Pacific Railway (which later became Ferrocarril General San Martín). This route was given the number 7.

In June 1942, work finished with the paving of the route between Chacabuco and Junín.Micro Ómnibus La Florida - Su Historia - BusArg They built the paved section between Junín and Laboulaye using a slightly different route (a little to the south), which separated the railway from the towns, and sped up the transport on that section. On 2 October 1969, the 67 km between Rufino and Laboulaye was opened, and then the 165 km between Junín and Rufino followed on 28 October of the same year. The paving reached Villa Mercedes in 1975. Here it formed a junction with National Route 8. Route 8 gives the republic's capital access to the east of the country, and has been paved since 1940.Automóvil Club Argentino (1969), Red caminera principal de la República Argentina

To reach Mendoza and Uspallata, the road goes through the "Caracoles de Villavicencio", a mountain section with altitudes of around 3000m, and 365 bends. Due to the danger of this part, they decided to create a new route in 1950. This would run along the banks of the Mendoza River, i.e. to the south of the existing route. The Directorate of National Highways tentatively started work on the new section in 1961, and it was completed in 1971. This took the paved section of road as far as Uspallata.

The next step was to upgrade the road to a highway for the section uniting the cities of San Martín and Mendoza. The work was carried out in two sections of 25 km (Mendoza - Las Margaritas) and 17 km (Las Margaritas - San Martín). The first section was completed in 1977 and the second during 1979. The second stretch included the construction of a new bridge, allowing the road to cross the Mendoza River.

They also designed and built a modification of the original section of the road starting near the Mendozan city of La Paz, diverting it approximately 1.5 km to the north, to pass nearer some towns. These had been considered to be on the old route by the less demanding criteria of the time. The original 140 km section was transferred to the jurisdiction of Mendoza Province, and is now called Provincial Route 50.

In 1979, National Directive 1595 transferred jurisdiction of the old Las Heras - Villavicencio - Uspallata (97.2 km) section to Mendoza Province, and it now forms Provincial Route 52. They also handed over the 53 km section from Luján de Cuyo to Potrerillos which is now Provincial Route 82, and the national orbit road linking the Mendoza section of Route 7 to Uspallata by way of Potrerillos.

The road to the west of Uspallata and its bridges that are in use today was completed between 1978 and 1979.

Another old section of Route 7 is the part leading to the Chilean border. This is a zigzagging road from Las Cuevas to La Cumbre Pass, where you can see the statue Christ the Redeemer of the Andes. There is a tunnel along the route belonging to the Transandine Railway, dating from 5 April 1910. This opened to mixed traffic in 1977, with the capacity to carry road transport as well as trains. A second tunnel (the Paso Internacional Los Libertadores) opened on 23 May 1980, parallel to the first. Since the new tunnel opened, the road to La Cumbre Pass has only been used for tourist traffic and only opens during the summer. Its current name is National Route A006 (Argentina).

Access from the city of Buenos Aires to Luján was formerly by an avenue circling parallel to the tracks forming part of Ferrocarril Domingo Faustino Sarmiento. The road was known as Avenida Rivadavia as far as Merlo. The government decided to hand this 52.55 km road over to Buenos Aires Province and to construct the Autopista Acceso Oeste to the north. This formed part of the Decree 1595 mentioned above. Buenos Aires Province eventually took it over in 1988, and the section of road became Provincial Route 7.

"Access West", the highway joining Avenida General Paz with Luján, was built in various stages over more than 20 years. It was finally completed on 1 September 1998. The last section joined Avenida General Paz with Morón. Building the road involved demolishing several kilometres of houses, because the road had to pass through the urban zones of Greater Buenos Aires.

In May 2001, construction started on the 212 km expressway (incorrectly known as a highway) in San Luis Province. It was funded by the province. It opened on 16 April 2003 and has the distinction of having lights along its entire length. It takes a slightly different route to the original road around the provincial capital and passes further south, i.e. further from the city centre. San Luis Provincial Law No. VIII-0258-2004 calls it "Autopista de las Serranías Puntanas" ("The Foothills of San Luis Highway"). The old 11.6 km section of road that it replaced passed into provincial jurisdiction. The government of San Luis converted it into an expressway which opened on 27 July 2007 as Avenida Parque Gobernador José Santos Ortiz.

Due to the construction of the Potrerillos Dam to the southwest of the city of Mendoza, they decided to build 10 km of road in a higher zone with two road bridges. This section opened on 23 August 2004. This part of the route generated controversy during the planning period because it passed through an important paleontological deposit.

The Santa Fe section

Due to the growth of Laguna La Picasa (:es:Laguna La Picasa) between 1998 and 1999, 14.5 km of the road was flooded. The affected area was between Aarón Castellanos and Diego de Alvear, along the border between the provinces of Santa Fe and Buenos Aires. This prompted the road to be rerouted on 19 April 1999.

The vehicles used a gravel track for 32 km, adding 17 km on to the original length of the road. Then they started to lower the water level in the lake by means of a pumping station in Rufino. That station will be complemented by another (not yet built) to the south of the lake.

Work started to repair the damaged section of road on 1 February 2006. It used stones brought from a quarry in San Luis Province. The stones were coated with mesh. By July 2006, they had joined up to the basalt stones on both sides of the lake. This allowed trucks to use the track, allowing them to continue with the work of raising the road. The road was to be raised 2 metres above the lake's maximum water level. In normal conditions it would be 6 metres above the lake's surface. The work includes a 60 m bridge in the centre of the lake. It is built in three 20 m sections, each with a lane for both directions of traffic.

This 10.5 km section came into use by traffic on 10 June 2007.

The construction was given the 2007 Road Engineering Works award by the Argentina Road Association, which covers all the provinces, industry and National Government sector.

Cities National Route 7 passes through several cities with a population of greater than 5000. These are listed below.

Buenos Aires Province

The route runs through 364 km of the north of Buenos Aires Province for km 12 - 376 of its total length. The road passes through the following partidos: Tres de Febrero (km 12-15): Ciudadela (km 13). Morón (km 15-24): El Palomar (km 17), Haedo (km 19) and Castelar (km 24). Ituzaingó (km 24-30): Ituzaingó (km 29). Moreno (km 30-44): Paso del Rey (km 32), Moreno (km 37) and La Reja (km 39). General Rodríguez (km 44-56): General Rodríguez (km 52). Luján (km 56-90): Luján (km 67). San Andrés de Giles (km 90-130): San Andrés de Giles (km 103). Carmen de Areco (km 130-166): Carmen de Areco (km 138). Chacabuco (km 166-237): Chacabuco (km 203). Junín (km 237-291): Junín (km 260). Leandro N. Alem (km 291-347): Vedia (km 315). General Pinto (km 347-376): no settlement with greater than 5000 inhabitants.

Santa Fe Province The road runs for 56 km in the extreme south-east of this province. This stretch starts 376 km into the total length, and leaves the province at 432 km.

General López Department (km 376-432): Rufino (km 426)

Córdoba Province

The road runs for 222 km in the south of Córdoba Province, for kilometres 432-654.

Presidente Roque Sáenz Peña Department (km 432-551):Laboulaye (km 490) and General Levalle (km 540). Río Cuarto Department (km 551-654): Vicuña Mackenna (km 586).

San Luis Province The road runs through San Luis Province for 221 km. It passes through the centre of the province for km 654 to 865.

General Pedernera Department (km 654-730): Justo Daract (km 661) and Villa Mercedes (km 696). Colonel Pringles Department (km 730-759): no settlements with population greater than 5000. La Capital Department (km 759-865): San Luis (km 788).

Mendoza Province

The route runs through 372 km of the north of Mendoza Province for km 865-1237. La Paz Department (km 865-926): La Paz (km 905). Santa Rosa Department (km 926-981): No settlement with more than 5000 inhabitants, except for the capital Santa Rosa (km 966). San Martín Department (km 981-1011): San Martín (km 999-1004) and Palmira (km 1007-1012). Maipú Department (km 1011-1027): Rodeo del Medio (km 1022). Guaymallén Department (km 1027-1040): Rodeo de la Cruz and Villa Nueva. Luján de Cuyo Department (km 1054-1139): Perdriel (km 1054). Las Heras Department (km 1139-1237): no settlement with greater than 5000 inhabitants. Tourist sites: Uspallata (km 1141), Los Penitentes (km 1212), Puente del Inca (km 1219) and Las Cuevas (km 1232).

In the section overlapping National Route 40, the road passes through Dorrego in Guaymallén Department and Luján de Cuyo in the department of the same name.

Tollbooths and services The road carries heavy traffic, so there are a lot of service stations along its length. But until 2004, the Junín - Villa Mercedes section did not have any service stations selling compressed natural gas (CNG), so vehicles that relied on this fuel diverted along National Route 8 instead.

Buenos Aires Province

km 15/mi 9.32: Shell service station (Ciudadela) km 26/mi 16.155: Tollbooth (Ituzaingó) km 26/mi 16.155: Shell service station (Ituzaingó) km 56/mi 34.796: ACA service station (General Rodríguez) km 57/mi 35.418: Tollbooth (Luján) km 62/mi 38.525: ACA service station (Luján) km 65/mi 40.389: Shell service station (Luján) km 87,5/mi 54.369: Tollbooth (Villa Espil) km 97/mi 60.272: YPF service station (San Andrés de Giles) km 103/mi 64: YPF service station (San Andrés de Giles) km 139/mi 86.37: ACA service station (Carmen de Areco) km 140/mi 86.991: Shell service station (Carmen de Areco) km 140/mi 86.991: Petrobras service station (Carmen de Areco) km 212/mi 131.73: CNG service station (Chacabuco)Enargas, Lista de estaciones de GNC por provincia . Retrieved 11 December 2009. km 246: YPF service station (La Agraria) km 258: Independent service station (Junín)