What is a good transport review paper?

1. Introduction

For more than a year now we have been privileged as editors-in-chief of Transport Reviews, trying to fill the big shoes of our predecessor Professor David Banister, while receiving great help of associate editors Michael Browne and Johan Woxenius taking care of freight-related papers. In 2021, around 400 articles will be submitted to the journal, with only a small share of this number being accepted (e.g. in 2021 only 37 papers were published), and most papers being rejected (desk-rejected or rejected based on comments from reviewers). Hence, we felt the time is right to write an editorial paper indicating what we expect from a transport review paper and what we do not wish to see in submitted papers. Doing so, we try to help future authors to maximise their chances of publishing in Transport Reviews, while also discouraging authors to submit papers that are not a good fit for the journal or papers that do not follow the guidelines. In this editorial, we explain the core elements of a good transport review paper and also give practical tips on how to write and publish a transport review paper, while also indicating which aspects we prefer not to see in papers submitted to Transport Reviews.

2. Elements of a transport review paper

2.1 A literature review

A literature review plays a central role in a transport review paper. Different types of literature reviews exist, often depending on the topic. Papers on a very specific topic (e.g. bicycle safety at roundabouts, Poudel & Singleton, 2021) or a very recent phenomenon (e.g. dockless bike-sharing systems, Chen et al., 2020) search for papers in databases such as Web of Science, Scopus or Google Scholar to find relevant papers based on specific keywords. For further guidelines of how to search for relevant papers, we refer to van Wee and Banister (2016). However, a review paper does not always need a detailed search for papers. Authors writing papers discussing classical debates in the field of transport (e.g. residential self-selection, Guan et al., 2020) or broader subjects (e.g. the impact of transport on well-being, Chatterjee et al., 2020) may rely on their own knowledge on which relevant studies to describe, since a search may result in too many studies. A literature review can also be supported by secondary data. This data can show transport-related evolutions over certain time frames and differences according to regions (for cycling, see for instance Pucher & Buehler, 2008). Some review papers follow a systematic approach and search in several databases when the review is more specific to make sure the full body of research on the topic is covered in the literature review. The inclusion of gray literature is always an option, especially for topics that have specific practical application as some reports generated by transport authorities can be of value to enrich the literature review.

2.2 Other elements adding value to a review paper

A review paper, however, is more than just writing a literature review; a review paper must make a clear contribution to the transport field. We argue that a review paper can do this in three ways: (1) by discovering new links and creating a conceptual model or framework, (2) generating new avenues for further research and (3) developing policy recommendations and providing insights for policy and practice (Figure 1).

Figure 1. Core elements of a transport reviews paper.

2.2.1 A conceptual model

A good overview of the existing literature can discover underexplored links which can result in the generation of a conceptual model or framework. Such a model can create new insights on a certain transport-related topic and can stimulate researchers to explore the suggested links in future research. For instance, the presented relationships between travel attitudes, residential location choice and travel behaviour by Cao et al. (2009) have resulted in many studies analysing residential self-selection. The conceptual model presented by De Vos et al. (2013) showing possible ways in which transport can influence different types of subjective well-being has stimulated the field of transport and well-being, while the framework of Liao et al. (2017) has been an inspiration for studies analysing consumer preferences for electric vehicles. Also recently presented conceptual models, e.g. on electrical vehicle charging (Teoh, 2022), accessibility (Vecchio & Martens, 2021) and transport services (Durand et al., 2022) are likely to impact future transport research.

2.2.2 Future research needs

Transport review papers can also focus on challenges that researchers are facing when trying to answer research questions and can suggest ways in how future studies should analyse a certain transport-related topic. This can refer to the use of certain methodologies which previously were ignored (e.g. advanced methods such as machine learning), but can also refer to the collection and use of certain data (e.g. cross-sectional vs. longitudinal; quantitative vs. qualitative), or the use of certain scales. Studies can also point to the need for investigating certain underexplored links or to focus on certain population groups. For instance, Handy et al. (2014) reviews challenges that researchers face in finding ways to stimulate cycling by highlighting limitations of the existing research, identifying remaining research needs and discussing methodological considerations for addressing those needs. In a recent study, Gkiotsalitis and Cats (2021) give suggestions for future studies on how to analyse recently emerged research gaps resulting from the significant drop in public transport ridership due to the COVID-19 pandemic.

2.2.3 Policy implications

A final way in how transport review papers can make valuable contributions to the transport field is by providing recommendations for policymakers, transport operators and transport planners. This practice is more common in the health field, where policies are derived from review papers based on an analysis of the evidence published previously and through doing a critical appraisal of the papers published on a certain topic. Based on the literature review, authors can suggest ways to make (passenger or freight) transport more sustainable, efficient and equitable, and how it may improve – or reduce the negative impacts on – people's health and well-being levels. Chatterjee et al. (2020), for instance, present potential policy actions to enhance the commuter experience and reduce the negative well-being impacts of long-duration commutes, while Gössling and Lyle (2021) give an overview of policies that can result in climatically sustainable aviation. Additionally, Sivanandham and Gajanand (2020) give policy suggestions for putting freight transport platooning into practice, while Pucher and Buehler (2017) give an overview of policies that can promote more and safer cycling. Volker and Handy (2021) recently contributed to the ongoing policy debate on the economic impacts of bicycle infrastructure on local businesses.

2.3 Tips for writing a good transport review paper

Authors considering writing a transport review paper should take into account several elements. First, potential authors should check whether previous studies have not already provided an adequate review of a certain topic, and whether there is room for an additional review (e.g. with a different viewpoint). Second, authors should evaluate whether writing a review paper on that topic is relevant and whether it can provide added value (e.g. by providing a new framework, policy recommendations or avenues for further research). Once decided to write a review paper, authors should clearly state how they searched for papers (e.g. to enable future replication of the search), i.e. which databases and keywords were used, whether time and geographical restrictions were applied and which type of papers were excluded. A figure explaining this process can be helpful. If no systematic search for papers was performed (e.g. due to a broad topic), this should be explained and justified. A review paper should not only give an overview of existing studies but should also evaluate the strengths and weaknesses of articles found, and indicate whether their methodology, results and conclusions are reliable. Finally, authors should try to (i) create comprehensive conceptual models/frameworks which can easily be understood and applied in future studies, (ii) state clear policy recommendations which urban/transport planners can easily put into practice and/or (iii) give clear suggestions for future studies on how to create better insights on the topic (e.g. by the use of certain data or methodologies).

2.4 What we are not looking for

We do not plan to publish papers performing primary data analysis (i.e. studies collecting and analysing data followed by a description and discussion of the found result), nor do we want papers to focus on a small geographical area (e.g. using one city/country as case study). A review of studies originating from a large area (e.g. a continent) is possible if this focus can be justified. We are also not looking for studies performing a detailed analysis or ranking of the authors, universities, countries and journals from which papers originate. This information can briefly be mentioned (e.g. in the introduction) if this can help in positioning the topic of the review paper, but it should not be the focus of the paper. A word cloud of keywords or the evolution in the number of papers per year are also types of analyses we do not see much value in. Transport reviews papers should also be easy to read for a non-expert audience. As a result, we encourage authors to avoid jargon and not make the paper too technical, e.g. by avoiding (too many) equations or mathematical formulations. It is important for authors to check the legibility of their figures and tables, since we often receive papers with unreadable figures or tables with too much information included. Finally, we encourage authors interested in publishing a paper in Transport Reviews to have a look at the authors’ guidelines, in order to avoid submitting papers which are too long (longer than 8000 words, excluding references), or having too many figures/tables or references (i.e. more than 6 and 100, respectively).

Disclosure statement

No potential conflict of interest was reported by the author(s).