Wrong-Way Driving (WWD) crashes have higher fatality rate than other crashes. In contrast to much of the existing literature, which has focused on collision data available after a WWD crash, this paper evaluates WWD events that did not result in a collision. The aim is to see if there are factors beyond those identified on collision-based studies leading to such events. The focus is on WWD events for highway exit ramps and evaluating the efficacy of in-situ countermeasures to mitigate such events. Data were collected by continuous monitoring of 12 exit ramps with potential WWD problems. Eight of the ramps received WWD countermeasures for mitigation purposes, and data were collected for these before and after mitigation. The results indicate that a major factor in a WWD event is driver confusion related to exit ramp geometry and signage, and that in-situ mitigation can be an effective countermeasure. This also suggests that increasing conspicuity of wrong-way entrance can potentially reduce the number of WWD crashes and fatalities.

Key words: Mitigation and remediation, Traffic safety, Traffic accidents, Data collection, Field tests, Highways and roads, Bibliographies, Ramps (road)