Elsevier — the academic publisher which publishes the most and the most highly ranked journals in transport research — has published a list of transport papers from its journals that have been downloaded the most over the first half of 2013. The list is available here and all papers on it can be downloaded for free until 31st October 2013.
One obviously has to be careful with attributing significance to lists of download frequency, for they don’t tell much about the reasons for the downloads — papers may, for instance, have been used for university courses with many students, or one or two individuals may have downloaded a paper repeatedly whilst working on a particular piece of research. Still, the list contains a number of papers one would expect to be there (e.g. Chapman’s paper on #2 and Banister’s on #7), and this tells us something about popularity and influence.
I wish to highlight two aspects of the list.
First, and to my delight, the Journal of Transport Geography has two papers in the top 5 — the aforementioned review on climate change and transport by Chapman and the position paper by Hesse and Rodrigue on the transport geography of logistics and freight distribution.
Second, there are some differences between Elsevier’s transport journals with the highest impact factor and the ones that feature most prominently on the list of most downloaded articles. For there are comparatively few papers from Transportation Research Part B and Part A. The journal that dominates the list of most frequently downloaded papers and particularly its higher echelons is Transport Policy, the impact factor of which is with 1.51 significantly lower than for Transportation Research Part B (2.94) or Part A (2.75). At the same time, the list confirms the position of Transportation Research Part E (IF=2.27) as a leading journal in the field.
Nonetheless, as a whole the list goes to show that the use of a single metric to rank journals is quite problematic. Insofar as journals are to be ranked — the usefulness of which I, like many others, have strong doubts about — multiple indicators should be used. No single indicator is perfect but if a broad range of different indicators is employed, it is possible to create a richer and more realistic picture of the position of any given journal in the wider field than with the current narrow focus on journal impact factors.