Officials opened the Interamericana Sur Friday but warned that there were eight to 10 sections where the road was reduced to one lane due to machinery or debris.
The vital highway to southern Costa Rica suffered heavy landslides during rains prompted by Tropical Storm Tomas in the first days of the month. The section between Palmar Norte and Paso Real had been closed since.
Transport officials at the Consejo Nacional de Vialidad urged motorists to stay off the road at night or in rainy conditions. They said cleanup work was to begin again today.
They also said that sections of the highway might be closed to allow machinery to work at any time. The alternate route, the Costanera Sur, still is open.