The Integrated Departure Route Planning (IDRP) tool combines convective weather impact forecasts from the Route Availability Planning Tool (RAPT) with departure demand forecasts from the MITRE tfmCore system to aid traffic managers in formulating plans to mitigate volume congestion in fair weather and during convective weather impacts. An initial prototype was deployed in the summer of 2010 for a very limited field evaluation. A second, more comprehensive field evaluation of the "Phase 2" IDRP prototype was performed in the summer of 2011. The key focus of IDRP is the planning and implementation of departure reroutes to avoid weather impacts and volume congestion on departure fixes and routes. This evaluation assesses three facets of the IDRP prototype critical to the successful realization of its concept of operations: 1. performance of weather impact forecasts from RAPT and departure demand forecasts from tfmCore, 2. effectiveness of reroute decisions, and 3. potential impacts on procedures and decision making based on observations of IDRP use in the field. The evaluation concludes with suggestions for future enhancements to improve the performance and realization of potential benefits in operational use of IDRP.