Iran has a state-owned railway system built to standard gauge (1,435 mm (4 ft 8+1⁄2 in)) which falls under the remit of the Ministry of Roads & Urban Development.

In 1886, during the time of Nasser-al-Din Shah, an 8.7 km 1,000 mm (3 ft 3+3⁄8 in) metre gauge horse-driven suburban railway was established south of Tehran, which was later converted to steam.

In 1943, 3,473 American soldiers of the Military Railway Service began running trains between the Persian Gulf and Caspian Sea using ALCO RS-1 locomotives rebuilt with 3-axle trucks and designated RSD-1.

[4] The Americans set up headquarters in Ahvaz, but were unable to tolerate the daytime heat, and generally operated the railway at night.

Diesel is a strategic industry, and by using this heavy oil as a fuel instead of gas for locomotives, the Islamic Republic of Iran has joined the 12 world countries which manufacture this type of engine.

Siemens is committed to exporting to Iran some 30 locomotives in the first phase, and to manufacturing another 120 using domestic capacities and expertise over the next 6 years (2007).

Furthermore, the construction of Chabahar-Zahedan-Mashhad railway, extending from southeast to northeast of the country to the length of 1,350 kilometers, started in 2010 with 3 billion euro credit.

A line to the Caspian Sea ends at the terminal of Amir Abad and at Bandar Torkaman, and is part of a north–south corridor to Russia and Scandinavia.

For the landlocked countries of Turkmenistan, Uzbekistan, Tajikistan, Kyrgyzstan, and Kazakhstan this line provides access to the sea.

A recent connection from Mashhad to Bafq has significantly shortened access to the port city of Bandar Abbas.

[citation needed] In total, Iran has signed a number of contracts with China for the development of 5,000 kilometres of railway lines.

[35] It is reported that during the late-Soviet era, some 350 railcars crossed the border at Jolfa daily, with the annual amount of cross-border freight reaching 3.5 million tons.

In April 2017, Russia and India celebrated 70 years of diplomatic relations and vowed to complete the North-South Transportation Corridor (NSTC) with the help of Iran.

[38][circular reference]There is presently no direct railway connection between Iran and Armenia, even though the two countries share a border.

[39] In 1996, Mashhad–Sarakhs extension connected Iran to Turkmenistan, as part of the Silk Road railway to link to the landlocked Central Asian Countries.

It will link Uzen in Kazakhstan with Bereket - Etrek in Turkmenistan and end at Gorgan in Iran's Golestan province.

[41] As of 2014[update], the Iranian line to Khorramshahr was finished,[42] but construction had not started on the track from the Iraqi border to Basra.

[citation needed] In 2017, the West Corridor known locally as Rahahane Gharb was expanded from Arak to Malayer and Kermanshah.

China Civil Engineering Construction Corp is building the Malayer-Khosravi corridor, which will eventually run to the border with Iraq.

[43][44] Mashhad-Khvaf-Afghanistan's Border-Islam Qala railway is being constructed by an Iranian firm, with funding from the Afghan government, but the section in Afghanistan remains incomplete.

[49] The new Khaf - Rahzanak rail line continues from Khaf to Torbat-e Heydarieh where it links with Mashhad - Bafq railway line a crucial rail link opened in 2009 which connects port city, Bandar Abbas in Persian Gulf with north eastern city of Mashhad and from there with Turkmenistan through Sarakhs.

The construction of the railway from Bam to Zahedan was completed in early 2009 connecting Tehran to Pakistan border with an opening ceremony on 19 July 2009.

[56] Speeds of up to 200 km/h for locomotive-hauled passenger trains and 250 km/h for tilting EMUs are expected to reduce existing journey times of 7.5 to 12 to less than 5 hours.