a continuous run of trains will be possible between Asia and Europe, which is now done by rail ferry service. But the Marmaray tunnel may give a limited service to freight trains due to dense usage by public transport. On 7 November 2019 the first Chinese freight train through the Marmaray tunnel to Europe ran, from Xi’an using a Chinese locomotive. This demonstrated a China to Turkey transportation time reduced from a month to 12 days. The Baku–Tbilisi–Kars railway also provides a route via the Caspian Sea by bypassing Iran, Uzbekistan and Turkmenistan. The new railway lines constructed in Kazakhstan will make it shorter. The new route, in this case, is China–Kazakhstan–Azerbaijan–Georgia–Turkey. Break of gauge issues The former countries of the USSR, as well as Mongolia and Finland, use a track gauge of . The international standard gauge used in most of Europe and China is . As a result, trains cannot run from China or European countries into or out of the former USSR without changing bogies. Large facilities to carry out this procedure exist at most border crossing between the "Russian" and "standard" gauge territories (e.g., at Zabaykalsk or Erenhot) Changing the bogies on a rail car takes hours and special, heavy equipment. In many cases (especially, containerized freight), freight is transshipped from one train to another instead of changing the bogies. As of 2016, this is the usual procedure with China-Europe container trains at places such as Khorgos; it is reported that containers can be moved from one train to another in as little as 47 minutes. In the case of liquids, frozen goods and hazardous materials, however, the bogies are usually changed. It has been suggested that on some lines variable-gauge axles would achieve significant time savings in comparison to bogie exchange. However, their implementation would involve a much higher capital cost, requiring either retrofitting or replacement of existing bogies. Proposed development Expansion projects On 10 March 2004 the Kazakhstan Railway Company Ltd announced that it was looking for investors to fund the construction of a railway stretching from China across Kazakhstan to the Caspian Sea that would be the same gauge as Chinese railways. Thus, the railway would allow trains from China to cross Kazakhstan without having to change bogies. The reported construction cost of the new railway was $3.5 billion. Chinese media reported that the railway would complete the link between China and Europe