 The network consists of two main lines.A 449 km passenger line that links Dammam with Riyadh, and a 556 km freight line that connects the King Abdul Aziz Port in Dammam with Riyadh In addition, about 373 km of auxiliary lines branch from SRO's main lines and connect some industrial and agricultural areas, and military sites, with export ports and residential areas.There are plans to extend the network to the Red Sea port of Jeddah and, eventually to the borders of Jordan, Yemen, and perhaps all the way to Egypt.