864791.fig.004
Figure 4: Relationship between the mean legibility distance and the contour size under 60 km/h, where the relationship between the mean legibility distance and the contour size under 60 km/h was for triangle: and , and for round: and . represents the size of the roadside object, unit is square meters, represents the mean legibility distance, unit is meter, and represents the degree of fitting, describing how well it fits a function.