Evaluation of Alternative Truck Lane Management Strategies along a Section of I - 81

Transportation network improvements are commonly evaluated by estimating average speeds from atransportation/traffic model and converting them into emission estimates using an environmental model such asMOBILE or EMFAC. Unfortunately, recent research has demonstrated that average speed, and perhaps evensimple estimates of the amount of delay and the number of vehicle stops on a roadway, is insufficient to fullycapture the environmental impacts of Intelligent Transportation System (ITS) strategies such as adaptive trafficsignal control. Specifically, for the same average speed, one can observe widely different instantaneous speedand acceleration profiles, each resulting in very different fuel consumption and emission levels. In an attempt toaddress this limitation, the paper presents the INTEGRATION model framework for quantifying theenvironmental impacts of ITS alternatives. The model combines car-following, vehicle dynamics, lane changing,energy, and emission models to estimate mobile source emissions directly from instantaneous speed andacceleration levels. The validity of the model is demonstrated using sample test scenarios that include travelingat a constant speed, traveling at variable speeds, stopping at a stop sign, and traveling along a signalizedarterial. The study also demonstrates that an adjustment in driver aggressiveness can provide environmentalbenefits that are equivalent to the benefits of adaptive traffic signal control.