The correct answer to this open question is the following.
Governmental projects should follow the guides of the project and standard rules to deliver specific deliverables, artifacts, and products.
There are always specific regulations that contractors must follow in order to participate in a special project of infrastructure. There are guidelines established by the government because public projects have to be transparent and are given to those companies that have shown they have the experience, capacity, and resources to carry the project from the beginning to the end and deliver it on time. Sometimes the standard is so hight that only specific companies can participate.