Road safety audits (RSAs) and the International Road Assessment Programme (iRAP) methodology have a common objective, to reduce road trauma, yet the two approaches are different. RSAs are a formal, systematic, and detailed examination of road safety concerns by an independent and qualified team of auditors. RSAs leverage the knowledge and experience of these auditors and only present issues the auditors believe present risks to the traveling public. The iRAP methodology is a highly standardized, data- and evidence-driven process that produces quantifiable safety metrics such as Star Ratings and investment plans.

Each of the RSA and the iRAP methodology has its own strengths and limitations; however, by combining the two, the potential of each can be amplified, and their limitations are minimized. Throughout this manual, the approach of combining RSA and the iRAP methodology is referred to as Star Ratings for Road Safety Audits (SR4RSA).