Assessing the Emission Impacts of IVHS in an Uncertain Future

Analysts today would like to assess the emissions impacts likely to result from future implementation of intelligent vehicle and highway system (IVHS) concepts. This requires making assumptions about the simultaneous emergence of technologies and policies. Assumptions about emission characteristics of the future vehicle fleet, the penetration of electric vehicle technologies, and the impacts on driver behavior of future policies has profound implications on research findings. This paper first summarizes the likely impacts of three IVHS technologies (Advanced Traffic Management Systems, Advanced Traveler Information Systems, and Advanced Vehicle Control Systems) given characteristics of current vehicle characteristics and driving behavior. Then, each IVHS technology is re-assessed with some change in a future assumption - be it technology or policy based - to determine the expected air quality impacts. It is found that future assumptions profoundly affect the expected air quality impacts of the three IVHS technologies, in most instances improving their outlook. The authors recommend that transportation planners and researchers consider synergism of technologies and policies, since this is the more likely way in which changes in the transportation paradigm will emerge. The authors acknowledge that assumptions about the future can be used to aid in the formulation of effective solutions to transportation problems.