SNIP measures contextual citation impact by weighting citations based on the total number of citations in a subject field.
SJR is a prestige metric based on the idea that not all citations are the same. SJR uses a similar algorithm as the Google page rank; it provides a quantitative and a qualitative measure of the journal’s impact.
The Impact Factor measures the average number of citations received in a particular year by papers published in the journal during the two preceding years.
© Thomson Reuters Journal Citation Reports 2015
To calculate the five year Impact Factor, citations are counted in 2014 to the previous five years and divided by the source items published in the previous five years.
© Journal Citation Reports 2015, Published by Thomson Reuters
Transportation Research Part D: Transport and Environment publishes original research on the environmental impacts of transportation, policy responses to those impacts, and their implications for the design, planning, and management of transportation systems. It covers all aspects of the interaction between transportation and the environment. For example, it includes papers ranging in their coverage from the local and immediate effects of transportation networks on the environments of specific geographical areas, to the widest global implications of natural resource depletion and atmospheric pollution.
The journal invites submissions of research papers on all modes of transportation, including maritime and air transportation as well as land transportation, and considers their impacts on the environment in the broad sense. Papers dealing with both mobile aspects and transportation infrastructure are considered. The emphasis of the journal is on empirical findings and policy responses of a regulatory, planning, technical or fiscal nature. Articles are primarily policy-driven and should be relevant and applied as well as being accessible to readers from a wide range of disciplines. There are no disciplinary boundaries to work considered and submissions of an interdisciplinary nature are welcomed. Equally, the journal is fully international in its orientation and invites contributions from economically developing, as well as more economically advanced, countries.
Part D's aims and scope are complementary to Transportation Research Part A: Policy and Practice, Part B: Methodological and Part C: Emerging Technologies. The complete set forms the most cohesive and comprehensive reference of current research in transportation science.