A system and method of implementing Routing Stability-Based Integrated Traffic Engineering ("RITE") for use in an MPLS/optical network is described. Incoming network traffic is classified as high priority ("HP"), which requires absolute routing stability, or low priority ("LP"), which can tolerate limited rerouting. In accordance with one embodiment, HP traffic trunks are mapped on to direct LCs and are rerouted only in the event of an LC teardown due to poor traffic utilization. LP traffic trunks are mapped on to direct LCs if available; otherwise, they are mapped on to multi-hop LSPs with appropriate O/E/O conversions at the edge nodes serving as intermediate hops. Each LP traffic trunk is associated with a rerouting timer that is set at the time of rerouting so as to prevent another rerouting of the trunk until the timer expires.