What Is the Middle Corridor, and What Role Does Türkiye Play in the Trans-Caspian Route?

Why It Matters

The Middle Corridor, formally the Trans-Caspian International Transport Route (TITR), is a multimodal freight route that carries goods between China, Central Asia and Europe by crossing Kazakhstan, the Caspian Sea, Azerbaijan, Georgia and Türkiye. It gained global attention after February 2022, when Russia's full-scale invasion of Ukraine pushed shippers, insurers and governments to look for alternatives to routes through Russian territory. Türkiye is the corridor's western gateway: its rail and port links connect the Caucasus to Europe, which is why the route features prominently in Ankara's connectivity policy.

Background

The Middle Corridor is not a single project with one owner. It is a chain of national railways, ports, shipping lines and customs systems that cooperate under an association and a series of intergovernmental agreements.

How the route works

The route is described below from east to west. Exact paths vary by cargo and operator.

• China to Kazakhstan: Cargo enters Central Asia by rail at the Kazakh–Chinese border and travels west across Kazakhstan.
• Across the Caspian Sea: Cargo is loaded onto ships or ferries at Caspian ports such as Aktau and Kuryk in Kazakhstan, and crosses to the Baku area in Azerbaijan, including the Alat port. Turkmenistan's Caspian port and the Uzbek rail network also feed this segment.
• Azerbaijan to Georgia: Rail lines run from Azerbaijan across Georgia to the Black Sea ports of Poti and Batumi.
• Georgia to Türkiye and Europe: Cargo either continues by rail on the Baku–Tbilisi–Kars (BTK) line into Türkiye and onward towards Europe, or goes by sea from Georgian ports across the Black Sea.

The railways of Central Asia and Georgia use the 1,520 mm gauge, while Türkiye and most of Europe use the 1,435 mm standard gauge. Cargo therefore has to be transshipped or the wheelsets changed at the border, which is one of the corridor's technical bottlenecks.

Key milestones

For the wider picture of Türkiye's straits, rail lines and ports, see The Crossroads Guide: How Türkiye's Straits, Rail Lines and Ports Connect Europe and Asia. For the pipeline side of the same geography, see Energy Corridors Through Türkiye: Pipelines, Gas Hubs and the Eastern Mediterranean Question and the sister analysis Türkiye as an Energy Hub: Pipelines, Corridors and Transit Routes Explained.

Volumes and capacity

Published freight figures and capacity targets differ by source, year, cargo definition and whether containers, bulk or oil products are counted. This article does not repeat those figures. Readers should check the statistics of each national railway and port authority directly, and the World Bank study for an independent assessment.

Key Players & Positions

Participating states

• Kazakhstan: The corridor's main Central Asian gateway to China, with Caspian ports at Aktau and Kuryk.
• Azerbaijan: The Caspian crossing's western terminus, with the Baku and Alat port area and rail links to Georgia.
• Georgia: The transit state between the Caspian and the Black Sea and Türkiye, with the ports of Poti and Batumi.
• Türkiye: The western gateway to Europe via the BTK railway, Marmaray, Black Sea and Mediterranean ports, and Istanbul's road and rail network.
• Uzbekistan, Turkmenistan and Kyrgyzstan: Central Asian states that feed cargo into the Caspian crossing or are linked to it by rail projects.
• China: The origin of much of the cargo and a major financier of Eurasian infrastructure.
• EU member states: The main destination markets, reached through Black Sea and Balkan routes.

The Organization of Turkic States connectivity agenda

The OTS has Azerbaijan, Kazakhstan, Kyrgyzstan, Türkiye and Uzbekistan as members, with Hungary and Turkmenistan as observers. Its Turkic World Vision 2040 document and summit declarations include transport connectivity, customs facilitation and digitalization among their priorities. In the OTS framework, the Middle Corridor is one practical expression of that agenda. The OTS does not own or operate the route. Operations remain with national railways, ports and shipping companies.

How other actors describe the route

• European Union: The European Commission presents Central Asian and Caucasus connectivity as part of its Global Gateway strategy and its revised trans-European transport network policy, which allows for links to neighbouring regions. The EU frames the corridor as a way to diversify supply chains and strengthen regional partners.
• China: Chinese official documents and Foreign Ministry statements place Central Asian and trans-Caspian links under Belt and Road cooperation and the China–Central Asia summit mechanism. Beijing speaks of connectivity in general terms and has not described the Middle Corridor as a replacement for other routes.
• Russia: Russian officials, in statements by the Foreign Ministry and the Kremlin, emphasize the International North–South Transport Corridor with Iran and India and Russia's own transit potential. On the Caspian, Moscow stresses that issues concerning the sea are for the five littoral states, in line with the 2018 Convention on the Legal Status of the Caspian Sea signed at Aktau.
• Regional states: Kazakhstan, Azerbaijan and Georgia present the corridor as a driver of transit revenue and economic diversification. Their transport and economy ministries and railway companies promote joint tariffs, one-stop services and port upgrades.

Source Comparison

Different sources emphasize different things. The table below sets out the typical framing and the primary source each rests on.

How to read the coverage

Media reports often frame the corridor as a bypass of Russia or as a rival to China's northern routes. Official sources use more cautious language of diversification and connectivity. The most reliable assessments rely on operator statistics and independent studies such as the World Bank's, and treat claims of rapid scaling with caution.

Constraints and rivals

• Caspian crossing: Shipping and ferry capacity, port handling and weather limit throughput.
• Gauge break: The change between 1,520 mm and 1,435 mm track adds time and cost.
• Multiple jurisdictions: Several customs regimes, tariffs and operators complicate a single through service.
• Competition: The northern route through Russia, the International North–South Transport Corridor, and sea routes via the Suez Canal or around Africa remain alternatives.
• Regional politics: Transit across the South Caucasus depends on the peace process between Azerbaijan and Armenia and on relations among the transit states.

Key Terms & Related Guides

• Middle Corridor / TITR: Two names for the same Trans-Caspian multimodal route. TITR is the formal name used by the international association of operators.
• Multimodal transport: Moving cargo by more than one mode, here rail, ship and sometimes road, under coordinated documentation.
• Gauge break: The point where railways with different track widths meet, requiring transshipment.
• Organization of Turkic States (OTS): A grouping of Turkic-speaking states, formed in its current name in 2021, that includes connectivity in its agenda.
• Global Gateway: The EU's strategy for connectivity investments with partner countries.
• Belt and Road Initiative: China's infrastructure and trade connectivity framework.
• Marmaray: The rail tunnel under the Bosphorus in Istanbul, opened in 2013, which links Asian and European rail networks.

Related reading on Recorridor:

• The Crossroads Guide: How Türkiye's Straits, Rail Lines and Ports Connect Europe and Asia
• Reopening the Kars–Gyumri Line? What Türkiye–Armenia Normalization Could Mean for Caucasus Transit
• Recorridor: Türkiye's Crossroads of Straits, Corridors and Borders, Explained
• Editorial Principles: How Recorridor Handles Facts, Positions and Primary Sources

From sister publications: Is Türkiye a Bridge Between Blocs? NATO Membership, Eurasian Ties and Strategic Autonomy.

Recorridor presents global and regional affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Position' reflect official Turkish policy and legal doctrines as stated by Turkish primary sources.