During the 2000s, several urban highways were built through Santiago in order to improve the situation for vehicles. The road General Velásquez and sections of the Pan-American Highway in Santiago were converted into the Autopista Central, while Américo Vespucio became variously the highways Vespucio Norte Express and Vespucio Sur, as well as Vespucio Oriente in the future. Following the edge of the Mapocho River, Costanera Norte was built to link the northeast of the capital to the airport and the downtown area. All these highways, totaling 210 km in length, have a free flow toll system.