The Chittenden County Model is an integrated land-use allocation, transportation, and air quality model designed to perform a wide range of analyses. The model includes several advanced features that place it on the cutting edge of improved modeling methods required to meet the needs of 2005 Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) and the Clean Air Act Amendments of 1990. In addition, several features recommended by the Travel Model Improvement Program of the US Department of Transportation and Environmental Protection Agency are incorporated into the Model.