Transportation lacks integration, owing to the mountainous terrain. For this reason, air transportation has become the most important means of travel for most passengers. Despite the development of roads and railways, river travel has remained the chief mode of transportation for cargo since the trip up the Magdalena River in 1536 by the Spanish conqueror Gonzalo Jiménez de Quesada. Inland waterways navigable by riverboats totaled 18,140 km (11,272 mi) in 2002. The Magdalena, the fourth-largest river in South America, is navigable for 950 km (590 mi); it carries almost all of Colombia's river traffic.
The railroads, which were nationalized in 1954 and deregulated in 1989, had a length of 3,304 km (2,053 mi) in 2002.
Also in 2002 there were about 110,000 km (68,354 mi) of roads, of which only about 26,000 km (16,156 mi) were paved. Many roads are plagued by landslides and washouts. The 2,800-km (1,700-mi) Caribbean Trunk Highway, completed in 1974, links the Atlantic ports of Cartagena, Barranquilla, and Santa Marta with the Pan-American Highway (south of Panama) and the Venezuelan highway system. In the early 1990s, the government proposed a 15-project program, with an estimated cost of $500 million. In 2000 there were 1,041,076 passenger cars and 418,531 commercial motor vehicles.
Owing to inadequate land transport, air service is essential and well developed. A flight from Bogotá to Medellín takes only half an hour, while a truck requires 24 hours over a winding mountain road. In 2001 there were an estimated 1,066 airports, only 96 of which had paved runways. Colombia's airline, Avianca, is the second-oldest commercial airline in the world and one of the largest in Latin America. Avianca handles about two-thirds of the domestic and international movement of passengers. Most of the country's air transportation is handled by the six principal airports at Bogotá, Barranquilla (E. Cortissoz), Medellín, Cali, Cartagena (Rafael Nunez), and San Andreas. In 2001, these airports serviced about 9,566,100 passengers.
Colombia's merchant marine is dominated by the Grand Colombian Merchant Fleet (Flota), a stock corporation owned by the Colombian Coffee Federation. In 2002, merchant marine companies had an aggregate of 11 vessels with 1,000 GRT or over, totaling 32,438 GRT. The nation's chief ports on the Caribbean are Barranquilla, Cartagena, and Santa Marta. Buenaventura is the only important Pacific port.