Uzbekistan officially also the Republic of Uzbekistan, is a doubly landlocked Central Asian Sovereign state. It is a secular, unitary, constitutional republic, comprising 12 provinces, one autonomous republic, and a capital city. Uzbekistan is bordered by five landlocked countries: Kazakhstan to the north Kyrgyzstan to the northeast; Tajikistan to the southeast; Afghanistan to the south; and Turkmenistan to the southwest.As of 2007, Uzbekistan’s overland transport infrastructure declined significantly in the post-Soviet era due to low investment and poor maintenance. Air transportation was the only branch that received substantial government investment in the early 2000s, as airport modernization projects were undertaken.In the following years, improvements have been made to the surface transportation network including the construction of the Tashkent-Samarkand high-speed rail line. As of March 2017, the total length of Uzbekistan’s main railway network is 4,669 km.