Emission allocation issues in repositioning transportation

ABSTRACT Various emission reduction methods have been investigated in relation to policy, technology, and operation in academia and industry. Increasing capacity utilization by sharing transportation network and gaining return cargo is one potential approach to achieve this reduction. As a consequence, repositioning of the vehicle is needed in some cases, which needs to be supported by a proper emission allocation scheme to encourage different players to form and maintain a sharing coalition. However, the presence of repositioning adds a level of complexity to the emission allocation issue since empty trips in repositioning transportation carry no cargo themselves to which the emissions can be allocated. For this purpose, we present alternative allocation schemes and investigate the impacts of these schemes on the carbon footprint measurement. A real-life case study is demonstrated and discussed based on a simulation model and analysis of variance (ANOVA). We find that different schemes have significant effects on the distribution of emission among the cargo owners. We suggest that a scheme to share the emissions based on total transport work is preferable because it provides motivation for a joint cooperation between players and improves the environmental performance. The methodology applied in this article can be generalized to other repositioning transport cases in which more players and more logistics legs including empty trips are involved. It also provides insight for policymakers to devise rules for carbon footprint calculations that encourage collaboration and shared transport in complex, multi-stakeholder transportation networks.