Untrained human observers are reliable judges of traffic conflict dangerousness.

Subjects were instructed to rate video- filmed traffic conflicts on a subjective scale of dangerousness. Although the concept "dangerousness" embraces different factors, it was hypothesized that subjects adequately apply this construct when judging traffic conflicts without further training. It was concluded that subjective judgement of dangerousness is a reliable and valid estimator of the measure employed by the DOCTOR technique. The use of subjective judgement of dangerousness will be demonstrated in a field study.