Irrespective of the scale of corruption, if it is roads and highways in BD, the costs will far supersede similar constructions in Pakistan. BD needs to haul/ transport or dig nearby for soil to elevate the surface of the road by about 4 meters from the original GL. It is always Flood Level + 1.0 m or more.Don't know why, but some time back there was a thread about 5-6 motorways project in Bangladesh and even it's per km cost was almost 4-5 times more than the average cost in Pakistan.
And Pakistan came very on top in corrupt countries as per transparency international. Speaks for itself.
Otherwise, flood water will overtop the road and break it.
Usually, people do not want to understand, but the heavy costs of soil banking works are not perceived with eyes after construction, but it may be the most expensive component of the construction.