Journal Article Title: Forensic Engineering Analysis of the Four-Way-Stop Intersection Illusion
Article Author(s): Parsonson, Peter S., Ph.D., P.E.
Volume: 21
Volume #: 1
Month: June
Year: 2004

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Right-angle crashes at two-way-stop-controlled intersections are sometimes caused by the stopped driver entering the conflict area under the mistaken impression that the intersection has four-way-stop control. The cause of the illusion is often a device installed by the engineer in an attempt to improve safety, such as a flashing Intersection Control Beacon, or is a 'normal' operational feature such as curb parking. Nine such cues, and suggested countermeasures, are explained herein. It is the 'design driver', rather than the average one, who errs in this way. This is a human-factors problem that engineers and psychologists should tackle jointly.