The BTK rail line, which extends from the bank of the Caspian Sea in Azerbaijan to the capital city of Georgia before carrying on to Turkey, where it feeds into the broader Turkish rail system to Europe beyond, was first envisioned in 1993 after an existing railway that went to Baku via Armenia was shut down due to the Nagorno-Karabagh conflict. However, decisive action wasn’t taken until 2007, when the leaders of Azerbaijan, Georgia, and Turkey met in Tbilisi and signed an agreement to make it a reality. Ten years later, the 846-kilometer long trade route has been commissioned and the first train is rumbling down its tracks as this is being written.
https://www.forbes.com/sites/wadeshepard/2017/10/30/new-silk-road-azerbaijan-georgia-and-turkey-unite-over-new-rail-line-armenia-further-isolated/#279e53793aff