From Savannakhet, Route 9 heads east through a series of drab and dusty towns, passing Muang Phin and then Xepon, where it begins its climb up into the Annamite Mountains. The road ends its Lao journey at the Lao Bao pass, before crossing into Vietnam and continuing down to Dong Ha, where it joins Highway 1. The French completed the road in 1930, as part of an Indochinese road network intended to link Mekong towns with the Vietnamese coast, bringing in Vietnamese migrants and trucking out Lao produce. Today, the Thais, too, have an interest in Route 9 as a trade corridor, linking their relatively poor northeastern provinces with the port of Da Nang in Vietnam.
While most travellers barrel through here on direct buses to and from Vietnam, the frontier is not without sites of interest. As you approach Muang Phin, Route 9 begins to cross the north–south arteries of the Ho Chi Minh Trail, a network of dirt paths and roads that spread throughout southeastern Laos, running from the Mu Gia Pass in Bolikhamxai province south through Attapeu and into Cambodia. While much of the debris from the war lies off the beaten track, some of these war relics are easily accessible. Another place worth stopping in to explore the surrounding area is the recently rebuilt market town of Xepon which, along with neighbouring towns, is populated predominantly by Phu Tai people, a lowland Lao group.