Highway officials say that two lanes are expected to be opened Thursday at a place where a slide closed the route. The location is in La Congreja on the Interamericana Sur at kilometer marker 37.
Workers have been trying to shore up the highway where one lane simply dropped down a cliff. In doing so the Consejo Nacional de Vialidad said that engineers found deposits of clay. That soil material is slippery when wet, so the job was to remove much of the clay and install drainage so that the soil under the highway would not become soaked.
Traffic is being detoured around the location now. Workers have dug into the adjacent mountain to obtain space for a second lane.
The work is being done 24 hours a day, said the Consejo.