Development of a novel model for co-modal emission calculation and inventory methodology.

This paper presents a novel model for co-modal emission calculation and inventory methodology combining the various modes of public transport. A number of available emission calculation models have been reviewed and the proposed methodology has been derived so as to cover all modes effectively in a homogenised manner. Due to the large number of different vehicle types and engine technologies involved, the current approach focuses on characteristics of each country in order to reflect country specific situation in the best possible way. Two case studies are presented. The first one compares two alternative co-modal routes based on their environmental performance, but also on other parameters such as time, distance and cost. The calculated emission factors are used in the second case study for the development of an emission inventory for the public transport sector in Greece. For this inventory, actual activity data from real life were collected from all transport operators in Greece, instead of using statistical data. The calculated results are compared against top-down approaches which use statistical data; this comparison shows that the proposed bottom-up methodology and final calculated data can serve as a basis and baseline scenario for future emission inventories. [ABSTRACT FROM AUTHOR]