It has to do with finding a good balance between what would ideally be required and practical limitations. The Model Minimum Uniform Crash Criteria (MMUCC) developed in the United States the European Union’s Common Accident Data Set (CaDaS) may serve as guidelines for other countries such as Korea. More information can be found on the websites of the United States (National Highway Traffic Safety Administration) and the European Commission. International databases, such as those of IRTAD, show many empty cells in this area. Given the fact that methods of data collection seem to differ in those countries that do provide exposure data, the data may not be comparable internationally. Many countries provide useful examples.