Background
Driving simulator studies are often carried out today to develop new driver assistance systems as well as to assess driver behaviour in different situations. These studies have a number of advantages (e.g. lower costs, accurate and easy detection of vehicle and driver data, easy control of the driving environment and traffic). At the same time, however, the validity of the results is regularly questioned and a lack of transferability to real traffic is criticised.
Aims
The DFG research project “Bestimmung und Quantifizierung von Gestaltungsmerkmalen einer realitätsnahen Fahrsimulation” (Determination and quantification of design features of a realistic driving simulation) dealt with the validity of the driver’s behaviour and the question to what extent the behaviour of a test person in a driving simulator is comparable to that in a real field test. To clarify this question, the influence of two independent variables on different validity parameters was investigated. On the one hand, design parameters of the driving simulator (horizontal viewing angle, motion simulation) were deliberately varied, on the other hand, selected scenarios were considered.
Method
The project included two phases with empirical research series. Firstly, the validity of the driver’s behaviour in critical situations was examined. Data from field studies already available at the IAD were used as the basis for this. The corresponding tests were simulated in the driving simulator in order to compare the respective measured values and to make statements about the validity.
In a second step, a test section was designed in the Darmstadt area, which contains three selected scenarios and was first traversed in the field in the context of a test subject study. Subsequently, it was reconstructed with the simulator software SILAB, in order to be able to carry out test series under identical conditions in a simulated environment. In this context, specifically selected design parameters of the driving simulator were successively varied in order to analyse their influence on the validity. By comparing the parameters obtained in the field and simulator, it was finally determined which driving simulator design leads to valid results in which scenarios.
Results
A comparison of the empirical results with the theoretically established assumptions shows that the driving simulator validity certainly depends on the influencing variables of the test scenario and design parameters. However, the direction and strength of these influences can neither be derived theoretically nor determined generally by an empirical study, since driver behaviour validity is an extremely complex construct. There are numerous connections between individual influencing variables and aspects of validity. Thus, the empirical study reveals the interesting result that an extension of design parameters does not necessarily lead to a neutral or even positive influence on the validity.
Funding
The project “Examination of the Driving Simulator Validity” was funded by the German Research Foundation (DFG) under project number 204086220 from 2012 to 2016.
