Vessels of 300 DWT or greater capacity carry mainly industrial and agricultural products. The main commodities handled are sand, rock, wood products, food grains, steel products, and logs. The majority of the traffic is domestic, but international traffic is important on the upper section among China, Lao, Myanmar and Thailand. Since the national road 13S was improved, river freight traffic between Vientiane and Savannakhet has fallen away, whereas there is still thriving river transport on the section between Vientiane and Luang Prabhang because the more severe terrain influences road transport costs on that section.