Discrimination and Estimation of Time-to-Contact for Approaching Traffic Using a Desktop Environment Abstract

Abstract

Each year, thousands of pedestrians are injured or killed in traffic accidents. Identifying pedestrians ’ perceptual capabilities for street crossing decisions is an important problem. This paper examines this issue by seeking to understand people’s time-to-contact judgments for short-range to long-range times-to-contact in a desktop environment. Two experiments were used to test time-to-contact judgments around 4, 7, and 10 seconds. Both experiments showed subjects videos of a car moving down a road toward the viewer. The first experiment observed subjects ’ ability to discriminate between two different time-to-contact values. The second experiment measured subjects ’ absolute time-to-contact estimates. We found subjects to be accurate at both discriminating and estimating timeto-contact in a desktop environment. However, performance worsens at longer time ranges, those that pedestrians typically use in street-crossing decisions. Our discrimination thresholds are consistent with other time-to-contact work, and thus illustrate that desktop environments are plausible settings to use for time-to-contact studies