Route 1 has a length of 1,168[1] kilometers and runs in a northwest-southeast direction. Starting in the town of Bermejo, the road roughly follows the Rio Bermejo, branching off at one of its tributaries. Running north to the town of Padcaya, the road intersects Route 28 (Bolivia), and continues north into the valley surrounding Tarija, in which National Routes 45 and 11 meet.
After passing through Tarija as a parkway, the road continues, running west over the mountains to the rest of the city and meeting Route 20 in El Puente. Here, the highway bears north again, running through the Rio San Pedro. Bearing West again, the road intersects National Route 14, and then enters Potosi. In Potosi, Route 1 and Route 5 run concurrently through the city center, and Route 1 then continues northwest.
Continuing in this direction, Route 1 intersects Routes 32 and 30 near the town of Challapata. Route 1 then runs along the edge of Lago Poopo,[1] joining Route 6 and entering Oruro. Joining the ring road, Route 1 continues for over 6 km[1] before leaving on an independent route. In the town of Caracollo, Route 4 joins Route 1 and they remain concurrent for roughly 90 km[1] before splitting in the town of Patyacama.
Continuing on, Route 1 continues roughly 90 km[1] again to La Paz, where Route 19 joins it. Near El Alto International Airport, the road turns at a cloverleaf interchange, running west. The road runs through El Alto. Intersecting Route 2, the highway leaves the suburbs, and runs 95 km to Desaguadero.
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