Getting there & away
Parque Nacional Lauca straddles Chile 11, the paved Arica-La Paz highway; the trip from Arica takes about three hours. There are several buses from Arica, mostly leaving on Tuesday and Friday. Other bus companies with daily service to La Paz, Bolivia will drop you off in the park, but you might have to pay the full fare.
Agencies in Arica offer tours, though most of the time is spent in transit. Renting a car in Arica will provide access to the park's remoter sites like Guallatire, Caquena and the Salar de Surire (the latter only with a high-clearance vehicle, since you'll ford several watercourses). Carry extra fuel in cans; most rental agencies will provide them. Do not forget warm clothing and sleeping gear, and take time to acclimatize.