The information below is provided by The Expatriates Saudi readers and is not verified by the webmaster. For the official lowdown, contact your nearest embassy.
Saudi
Arabia
All domestic air services are run by Saudi, which is quite reliable and reasonably priced. The most frequent and efficient service runs Jeddah-Riyadh-Dhahran. If you're not pressed for time and you don't have a car, the bus is a pretty good option. The bus company, SAPTCO, has comfortable, air-conditioned buses, but you can only buy tickets one day in advance or on the day of travel. Service taxis go to most of the same destinations as buses for around the same price, but don't run to a timetable.
Saudi Arabia has the only stretch of railway track in the entire Arabian peninsula - one line from Riyadh to Dammam, via Hofuf and Abqaiq. Trains run three times a day. If you plan to drive, a western driving license is acceptable. Rental rates are government controlled and comparable to rates in the West. Theoretically Saudis drive on the right; car insurance, sensibly, is compulsory.