In-service performance evaluation of bullnose median barriers in Iowa

This paper presents results of an in-service performance evaluation of the bullnose median barrier used in the state of Iowa. The data were collected in a four-county portion of Iowa during a 24-month data collection effort from 1997 to 1999. The bullnose barriers in the data collection area were usually installed consistent with Iowa DOT policy and represent good quality installations. Their collision performance was assessed in terms of collision characteristics, occupant injury, and barrier damage. While the data set for this study was small, examination of the collisions indicates that impacts at and near the nose often resulted in unacceptable vehicle behavior and severe occupant injuries. The data suggest that there is a need to develop median treatments that prevent vehicles from penetrating the system and contributing to injuries of vehicle occupants.