This paper develops a Model Of Sustainability And Integrated Corridors (MOSAIC) to select the best program-level plans for corridors within Maryland by estimating the sustainability impact of multimodal highway improvement options early in the transportation planning and environmental screening processes with minimum requirements on staff time and other resources. Six categories of sustainability indicators (mobility, safety, socio-economic impact, natural resources, energy and emissions, and cost) and more than thirty sustainability performance measures have been defined as evaluation criteria for the selection of highway corridor improvement options. MOSAIC is capable of evaluating ten multimodal corridor improvement options when employed in both either single or multi-improvement scenarios. The pivot-point mode choice model and six sustainability evaluation modules used in MOSAIC are discussed in detail. A case study of the US-29 corridor within Maryland is conducted to demonstrate the feasibility and usefulness of MOSAIC. Results show that the selection of the most desirable improvement option depends on policy priority, e.g., green improvement, mobility focus, or balanced approach. This corridor planning tool is now being integrated into the enterprise GIS system for statewide applications in Maryland.