The dual-gauge (1520mm and 1435mm gauge) bridge will connect the Azerbaijan Railways (ADY) railhead at Astara with the Iranian town of the same name, where it will join the Iranian Islamic Republic Railways (RAI) network. RAI completed construction of the line from Qazvin to Rasht in 2015 and the remaining Rasht - Astara section is due to be commissioned in 2017.

The 82m-long three-span Astarachay bridge will completed by the end of this year.

The Qazvin – Rasht – Astara railway is part of a north - south corridor across Iran stretching from the Gulf port of Bandar Abbas to Azerbaijani border. RAI forecasts the construction of the line will increase freight volumes on the Iranian network by 6 million tonnes initially and up to 15 million tonnes in the longer-term.

Moreover, Iran and Azerbaijan are discussing the possible connection of the Nakhchivan – Culfa – Tabriz and Baku – Tbilisi – Kars lines by constructing a new line linking Tabriz with Astara. This would connect the Nakhchivan Autonomous Republic, a landlocked exclave of Azerbaijan, with the contiguous part of the republic.