About 17,850 km (11,092 mi) of railroad tracks traverse Kazakhstan. Highways totaled 189,000 km (117,445 mi) in 2002, of which 108,100 km (67,173 mi) were paved. In 1994, General Motors Corp. signed an agreement to distribute North American-built vehicles in Kazakhstan. The primary port is Guryev (Atyrau), on the Caspian Sea. There are 3,900 km (2,423 mi) of inland waterways on the Syrdariya and Ertis Irtysh rivers. Much of the infrastructure connects Kazakhstan with Russia rather than points within Kazakhstan. Landlocked in the center of Eurasia it is dependent on its transport connections through neighboring countries to deliver its goods to world markets. In 2001 there were 449 airports, 28 of which had paved runways. In the same year, 501,000 passengers were carried on scheduled domestic and international flights.