the record for world's longest straight road, with the section from Haradh to the Batha' border with UAE cutting through the Rub' al-Khali desert, beating the previous record holder, Australia's Eyre Highway, by . On 19 February 2018, the speed limit on sections of Highway 15, Highway 40 and Highway 65 was increased from 120 km/h (75 mph) to 140 km/h (87 mph). Rail transportation The historic 1,300 km (810 mi) 1,035 mm (3 ft 511⁄32 in) narrow-gauge Ottoman Hejaz railway was mostly destroyed during the First World War and its stations in Mada'in Salih and Medina have been converted to museums. Within two decades of the unification of Saudi Arabia, the first Dammam–Riyadh line was completed in 1951, and was long. This line was later converted to only be used for freight transport, with a new, shorter, line being completed in 1985, exclusively for the transport of passengers. The other passenger line in the kingdom is the Riyadh–Qurayyat line, which runs through the middle of the country connecting the capital Riyadh to Ha'il, Majma'ah, the Al Jawf Province and Jordan via Qurayyat. It is the longest line in the Saudi rail network, and with a feeder line connecting it to the port of Ra's al-Khair, its total length comes up to around 2,750 km (1,710 mi). The North–South Railway line uses portions of the Riyadh–Qurayyat line and connects the main line to phosphate and bauxite mining locations in the northern reaches of the kingdom. Apart from mass transit systems such as metros, the only high-speed railway line in the kingdom is the Haramain high-speed railway line, construction of which was completed in 2017. The line is 453 km (281 mi) long and connects the two Islamic holy cities of Mecca and Medina via the King Abdulaziz International Airport in Jeddah and the King Abdullah Economic City. Air transportation Saudia, the flag carrier of the kingdom, started out in 1945 with a single twin-engine Douglas DC-3 Dakota gifted by US President Franklin D. Roosevelt. Over the century, the airline has now expanded to a fleet of more than 140 aircraft, transporting 34 million passengers annually to 95 destinations around the world. Saudia also operates the 13th-longest flight by distance in the world, SV 41, a flight from Jeddah to Los Angeles. Other airlines, mostly low-cost carriers, have gradually become commonplace in the kingdom, the largest being Flynas. Founded in 2007,