This study examined the potential emissions and energy impact of increasing the federal gross vehicle weight exemption to more sections of Maine’s interstate highway system. This would allow vehicles that weighed up to 100,00 pounds to frequent these additional parts of the interstate highway. The study evaluated the performance of a 6-axle configuration that operated at 100,000 pounds. Two parallel routes were traveled between Augusta and Brewer, Maine. Two different travel scenarios were developed using a simulation model. Results were computer for a “No Stop” option and an “All Stops” option. The “No Stop” options assumed uninterrupted travel, requiring no deceleration, through all traffic lights. The “All Stops” scenario assumed that the truck decelerated and stopped for 20 seconds, and then resumed the posted speed limit, at each traffic light. Findings are provided for both options.