Complex sentence: Rail transport in Saudi Arabia is managed by Saudi Railway Organization, which provides freight services on three main lines totalling 1018 km. These connect Riyadh with the Persian Gulf port of Dammam.
Split into simpler sentences: Rail transport in Saudi Arabia is managed by Saudi Railway Organization. It provides freight service on three main lines, 1018 km total, which connect Riyadh with Persian Gulf port of Dammam.