During development of innovative automotive safety features (and therefore well before market introduction) it is common practice for OEMs and their suppliers to do predictive analyses of the anticipated benefit of these systems. It is also common practice that stakeholders do a retrospective analysis once the system in focus is in production. Real-world data is then used to identify the “true” effect of the new system. There are however certain constraints to this approach. The varying degree they are met explain the difficulty to find consistent results and also the time span it takes before such results can be taken with any degree of certainty. It is therefore not surprising that even for systems that are now widely recognized as highly efficient it has taken several years before effectiveness numbers turned out to be stable.