The 1,860.5 kilometer-long Tazara railway spanning from Tanzania's commercial center Dar es Salaam to Zambia's Central Province represents one of China's largest foreign aid projects. A tripartite agreement was signed in September 1967 to build the railroad and construction began in 1970. The railway opened in 1975 and in July 1976 was officially transferred to the governments of Tanzania and Zambia, with the Tanzania-Zambia Railway Authority undertaking operations.