The modern expressway is located at the west side of the Metropolitan Area of the Great San Salvador.

In its path way, crosses very densely populated neighborhoods and to cope with the noise pollution problem, the designers decided to pass such areas with a sunken causeway; such solution posed an extra problem: The safety of the houses flanking the road; they had to be protected against differential settlement during the construction phase and during the life time of the project.

A solution of staged excavations with soil nailing stabilization was chosen to cover heights ranging from 7 to 11m.