Saudi Arabia follows strict rules when it comes to crossing the country's borders. You can easily choose air transport from many countries. There are some countries for which Saudi Arabia has closed its borders like Oman and Iraq. However, road transport between Saudi Arabia and other nearby countries is easy if you have all the documents.
The major international airports in the country are located in Jeddah, Riyadh, Dammam and Madinah. There are regular and non-stop flights between Saudi Arabia to major countries. Prominent airlines of the country are Saudia, SaudiGulf, Mid East Jet and Flynas.
Saudi Arabia shares its borders with Iraq, Kuwait, Oman, UAE, Jordan, Yemen, Qatar and Bahrain. There are no buses from major cities of Oman to Saudi Arabia. Regular buses connect Dubai to Mecca and Jeddah. Amman in Jordan is also connected to major cities of the country through buses. Doha in Qatar is connected to Saudi Arabia via comfortable public transport.
Currently, the rail network in Saudi Arabia serves only domestic cities. There are no trains from neighbouring countries to Saudi Arabia.
Saudi Arabia is very strict regarding entering its borders via a car. Currently, it has closed its borders for Iraq and Oman. You can easily enter the country from UAE, Bahrain and Qatar if you have all the necessary travel documents.