An evaluation of environmental benefits of time-dependent green routing in the greater buffalo-niagara region

This article conducts a realistic assessment, using a real-world case study, of the likely environmental benefits of an intelligent transportation systems (ITS) strategy that provides dynamic route guidance to travelers based on the lowest emission or fuel consumption routes. Several features distinguish this study from previous reported research. First, the research utilizes a realistic case study of a medium-sized metropolitan area in the United States. Second, the research applies the latest state-of-the-art models on both the transportation and the environmental modeling sides, through the development of an integrated model combining the Transportation Analysis and Simulation System (TRANSIMS) model and the Multi-Scale Motor Vehicle Emissions Simulator model (MOVES). The integrated model is then used to approximate "green user equilibrium," and to investigate the impact of market penetration on the likely environmental benefits of green routing. Third, the article also proposes a "targeted" traveler selection strategy whereby travelers with the greatest potential to reduce emissions or fuel consumption are selected for rerouting. Results indicate that green routing could result in significant reductions in emissions, but that this naturally comes at the expense of an increased travel time. For one scenario that considered assuming a traffic stream of only passenger cars, green routing resulted in an almost 13% reduction in carbon monoxide (CO) emissions, and a corresponding 8% increase in travel time. The results also indicate that tangible emissions reductions are achievable at low to medium market penetration levels for green routing applications, especially when travelers with the largest likely emissions savings are targeted.