The Northeast Area of the Postal Service recently completed an assessment of the environmental and economic impacts of deploying alternative fuel vehicles (AFVs) in Connecticut and Massachusetts. The study was conducted in accordance with procedures established by the President's Council of Environmental Quality (CEQ) to implement the National Environmental Policy Act (NEPA). This assessment produced a new computer model which is capable of comparing the environmental and economic impacts of various alternative fuel fleet options. The model was developed to be flexible in that it is able to compare various technologies and vehicle mixes and can also function as a data sensitivity testing program. The AFV assessment computer model provides the Postal Service with the tool needed to continually assess the environmental and economic impacts associated with rapidly changing AFV technologies.