The Three Faces of Synthesis: Bringing Together Quantitative Findings in the Field of Transport and Environmental Policy

Good policymaking is based on sound information. Seldom, however, does any research work generate findings that are genuinely new. Much research draws upon and extends bodies of existing knowledge to gain better insights or to refine the accuracy of key parameters. Modern information-retrieval systems allow increasingly easy access to the findings of previous work. One of the bigger challenges today is to keep abreast of what is actually going on, and to extract insights from the existing body of knowledge where gaps still exist and the most fruitful research may be conducted. There are three broad approaches towards our existing body of knowledge, and the aim of this paper is to examine the usefulness of these alternatives and to pinpoint the types of circumstance where one may prove more helpful than the others. It places particular attention on work done which relates to the effects that transport has on the environment.