Edinburgh Napier University

  Driver eye height and object height are key factors in the derivation of basic parameters for safe and economically efficient highway design. This study critically reviews previous approaches to the measurement of these values and investigates the changes in them over time. Previous methods of measurement were found to have considerable limitations in terms of coverage or accuracy. A new approach is developed for the naturalistic recording of a sample of vehicles using the principles of photogrammetry, the first time this approach has been used for all vehicle types. A field survey on a typical single carriageway UK trunk road was undertaken and the driver eye and object heights of vehicles using the route were recorded. The work confirms the consumer trend for larger vehicles with a consequential increase in driver eye height and object height. It finds the values used in current design standards are conservative and robust but potential exists for further review. The results of this study will be useful to roads authorities internationally in defining their own highway design standards.