An agreement was signed by the presidents of the three countries in 2007 and construction began in 2009. The 146km section of the route from Uzen, Kazakhstan, to the Turkmen border near Bolashak was the first section of the route to be completed in 2012 and the 82km Iranian section from Gorgan to the border at Incheh Borun opened last year. The line is 1520mm-gauge as far as Etrek, with the Iranian section of the route being standard gauge.
Completion of the Turkmen section of the route suffered a number of delays and the government terminated its contract with Pars Energy after it emerged the portion of the line being constructed by the Iranian contractor would not be completed by the December 2012 contractual deadline.
The line is initially forecast to carry five million tonnes of freight per year, rising to 10-12 million tonnes in the longer-term.