The idea is to allow construction contractors to propose alternative pavement designs that optimize individual means and methods to enhance highway project constructability.
This is a very interesting question. However, proposing equivalent design is a change that will have contractual consequences. Judging the equivalency requires proven record of at least equivalent performance. This is difficult to prove. Also, the constructability issue is important during design phase. After signing a contract, the owner should not be that concerned with constructability because it is now a contractor's concern.