The modern road system dates from 1967. As of 2002, there were 1,230 km (764 mi) of highways, of which 1,107 km (688 mi) were paved. Qatar has overland truck routes from Europe through Sa'udi Arabia via the Trans-Arabia Highway and road links with the United Arab Emirates and Oman. In 2000, there were 101,700 passenger cars and 71,000 commercial vehicles registered. Qatar has no railways or waterways. In 2001, there were 4 airports, 2 with paved runways. Doha International Airport is served by twenty international airlines. In 2001 1,134,600 passengers were carried on scheduled domestic and international flights. Qatar maintains modern deepwater ports at Doha and Umm Sa'id, where a tanker terminal is located. Qatar's National Navigation and Transport Co. enjoys a monopoly on arriving shipments. In 2002, the merchant fleet consisted of 25 vessels with 679,0181 GRT.