The purpose of this research is to discuss the minimum field of view a truck requires for driving in a straight line. We call this the drivable field of view (DFV). The approach we took consists of investigating the drivers, vehicles, and road environments.

The necessary basic data for analyzing DFV were obtained. For example, the visual targets were analyzed from the records of the lines of sight of truck drivers. In addition, the drivable sight distance (DSD) between visual targets and driver was calculated based on gap acceptance and reaction time.

The DFV was calculated using the visual target positions determined by actual road-traffic surveys, DSD, and the position of the driver‘s eye-point. The results show that the DFV is a fairly narrow area within the forward field of view. DFV is useful for determining the area which must be wiped by the windshield wipers of trucks in bad weather.