One important strategy for reducing energy consumption and harmful emissions involves shifting transportation demand from private to public modes. Calculations of average emission units (based on traffic performance) promise to improve the status quo. However, on closer examination of individual transportation demands, these calculations prove faulty in some areas. In traveling from point A to point B, an individual's energy consumption and emissions vary based on the choice of mode of transportation, pre- and posttrip travel, and different capacity use and energy sources of vehicles. All these aspects are taken into consideration in a newly developed methodology, and their effects on primary energy use and emissions are analyzed for different transportation modes. During actual trips, energy consumption and emissions are precisely calculated, taking into account not only the operating conditions of the vehicles but also the construction and maintenance of the roads and railways as well as vehicle production, maintenance, and disposal. This new method enables a more precise examination of typical planning tasks. To this end, transportation needs for peak-hour, shopping, and leisure traffic are investigated. Urban as well as interurban and rural routes are examined. The results show the impact of the different parameters to be considered in the calculations. For this reason it is necessary to consider all these influences in every particular case instead of adopting general opinions.
Abstract