There are no railways or navigable inland waters. All important towns and districts can be reached by bus and truck via interurban roads. In 2004, Iceland’s roadway system totaled 13,004 km (8,088 mi), of which only 4,331 km (2,694 mi) were paved or were surfaced with oiled gravel. Registered passenger cars in 2003 numbered 161,721 and there were 27,977 commercial vehicles.