The transport ministry said that each bridge can support 40 tons, so there will be no weight restrictions except for those that are normally enforced on the highway during peak hours.
The Ministerio de Obras Públicas y Transportes said that a bypass that takes one of the eastbound lanes of the highway will remain in effect. Workers created the bypass by knocking out part of the concrete center divide.
The washout that became an embarrassing hole suddenly appeared late June 26 in both of the westbound lanes. A bus driver has been credited with spotting the developing hole and putting up flares to prevent an accident.
Each bridge is 30 meters, about 98 feet. Under the bridges workmen are attempting to replace the drainage system that failed and caused the road to collapse.
Traffic officials admitted that the problem was one of lack of maintenance. President Laura Chinchilla visited the site over the weekend.
The bridges were in place Sunday, but workmen has to construct ramps because the bridges were higher than the road surface. Workmen also had to apply highway markings.
Ministry officials said that they still expected jams even though traffic is lighter this week due to mid-year vacation.
They said that some motorists might want to continue using the alternate routes through Heredia and on Ruta 27, the Caldera highway, that carried a lot of westbound traffic last week.