Section 3, we model the integrated secondary route network design problem in its equivalent problem, an integration of dual degree and time constrained directed out-trees. It is a binary integer program in a link formulation. An implicit enumeration on links with an embedded degree and time constrained spanning tree algorithm is developed in Section 4, to determine the optimal operations plan. In Section 5, we use the second largest time-definite express carrier in Taiwan for numerical computation. The conclusion and managerial implications of this research are presented in Section 6.