Camera Monitor Systems as a source for driver information

Camera monitor systems (CMS) can be used in motor vehicles to display the rear view for the driver on one or several monitors integrated in the vehicle interior. This may provide the possibility of replacing conventional exterior mirrors with suitable CMS. Thus, from a technical point of view, the compulsory information about the rear road traffic can be represented at any position in the field of view of the driver. In a previous study, the Bundesanstalt für Straßenwesen (BASt, German Federal Highway Research Institute) compared CMS with conventional side mirrors regarding technical aspects as well as in terms of human-machine-interaction (HMI). The purpose of the MMI study was to evaluate empirically preferred monitor positions as well as the distance and speed perception at low driving speeds. It is currently still unclear whether the same performance in perceiving distance and speed via monitor compared to conventional side mirrors is also ensured at high driving speeds.

At present, the possibilities to display driver information inside the vehicle are becoming more and more diverse. Individual monitors – especially in the instrument cluster – can be used to display the rear image of several cameras fused. These approaches may demand specific requirements of the driver. Analogous to conventional side mirrors or non-fused displays on a monitor:

  • the driver must be able to perceive the scenery and object representation with comparable accuracy in a comparable time in order to move safely in road traffic.
  • the discrimination between different objects as well as between different representations of the locating must be possible at all times.
  • it must be ensured for the driver that the (direct) all-round view – the driver’s gaze behavior – is maintained despite the presentation of rear (indirect) information in a central position.

Commissioned by the BASt, HFC performs different psychophysical studies in a driving-active context, divided into the project phases (A, B, C). In project phases A and B, driving tests are carried out in real driving environments (motorway, highway, city) with the investigation objectives of the monitor positioning and the fusion presentation with regard to the perceptive performance and then empirically examined. In project phase C, the distance and speed perception compared to the outside mirror are tested in a high speed experiment on a closed terrain (airport landing stage). Conclusively, the three project parts will show possible requirements for future CMS.


  • Literature analysis
  • Evaluation
  • Questionaires
  • Messtechnik


  • Test drives
  • User studies
  • Statistical data analysis