Have we reached satisfactory methodologies to approach the subjectivity in driver-in-the-loop simulators? A systematic review

Driver-in-the-loop (DIL) simulation has become crucial in the automotive industry, providing a controlled setting for assessing vehicle performance, driver characteristics, and scenario configurations. However, the incorporation of human factors introduces subjectivity into simulation outcomes. This systematic review examines the interplay between objective metrics (OM) and subjective assessments (SA) in DIL vehicle dynamic simulator research. To achieve this, PubMed and ScienceDirect databases and predefined keywords and boundary conditions are used. Through four eliminatory revision stages, most of the ultimately selected papers are scrutinized to determine if a viable methodology exists for addressing subjectivity in DIL simulations. The results indicate that most studies found a correlation between the OM and the SA. Another positive aspect supporting this conclusion is that most works are associated with the fidelity of virtual tests in vehicle simulators. Despite the initially positive findings, it is noteworthy that most studies utilized a mix of standardized questionnaires and custom surveys, highlighting both the challenge of relating works due to a lack of standardization and the need for caution regarding the implicit subjectivity in questionnaire creation for each research. In addition, some secondary results are discussed based on the metadata gathered.