The country is preparing for this year's rain season after flooding and landslides left a trail of death and destruction in the central highlands.
The national government will assume most of the financing for the Calle 68 and Ciudad de Cali corridors, which are expected to act as feeder lines for Bogotá's future metro system.
The country's northern coast and jungle, which have been devastated by heavy rains over the past two years, will see a major infrastructure investment drive in 2019.
The initiative was backed by a mixed committee in congress, which also added new sources of money for the fund.
President Juan Carlos Varela visited the project site to inspect the progress of the works to widen the road.
Another retired general, who is expected to fill the position, has now being included into the president-elect's transition team.
The funds are divided between an addition to the current contract to complete the tunnel itself and three new tenders to complete complementary roads and 19 short tunnels.
Construction of the 12km road in the coastal towns of Reñaca and Concón began in 2011 and so far US$21mn has been spent.