Conceptual and Methodological Issues in Evaluations of Road Safety Countermeasures

Researchers have a long history in the conduct of evaluations of road safety countermeasures. However, despite the strengths of some evaluative road safety evaluations that align with previous and current thinking on program evaluation, few published road safety evaluations have followed standard conceptualization and methodology outlined in numerous program evaluation textbooks, journal articles and Web-based handbooks. However, conceptual and methodological challenges inherent in many evaluations of road safety countermeasures can affect causal attribution. Valid determination of causal attribution is enhanced by use of relevant theory or hypotheses on the putative mechanisms or pathways of change and by the use of a process evaluation to assess the actual implementation process. This article provides a detailed description of the constructs of causal chain, program logic models and process evaluation. This article provides an example of how these standard methods of theory-driven evaluation can improve the interpretation of outcomes and enhance causal attribution of a road safety countermeasure.