The highway agency used a poor boy approach to build bridges on an access route to the controversial Ruta 1856.
The bridges are made of wood.
The four new bridges are on Ruta 507, a 49- kilometer gravel road that connects Puerto Viejo de Sarapiquí with Fátima, which is a community on Ruta 1856.
The Consejo Nacional de Vialidad reported that its workers did the jobs themselves, based on instruction they had received in the United States.
The wooden bridge decking is tied to the wooden beams underneath with chain.
The agency said the bridges can support up to 13 tons. The agency said the cost was about 6.5 million colons, about $13,000, instead of the estimated 90 million colons or $180,000 that more conventional methods would have cost.
The Ministerio de Obras Públicas y Transportes also is working on Ruta 1856, which borders the Río San Juan. That route is the subject of corruption investigations, and contractors hired to do the work have been replaced by state employees.
There is a good chance that the wooden bridges also will find a place on Ruta 1856 where contractors used old shipping containers are the foundation for bridges.