Fig 1.
Interface for driving speed estimation system showing examples of the narrow and wide road types and 4 image scales (upper left-scale 1.0, upper right-scale 0.75, lower left-scale 0.5, lower right-scale 0.38).
Table 1.
The distribution of the 192 driving video clips.
Numbers in parentheses are speed mean and standard deviation of the column or row.
Fig 2.
Underestimation of speed increases with increasing image size.
Fig 3.
Participants with driving experience accurately estimated speed for wide and narrow roads whereas participants without driving experience underestimated speed with greater underestimation on wide roads.
Fig 4.
Effects of gender and driving experience on speed estimation.
(a) Females had greater estimation errors than males with the greatest differences at the highest and lowest speed groups. (b) Participants without driving experience increasingly underestimated speed as speed increased whereas participants with driving experience only underestimated the highest speeds.