This paper reports on unsafe actions of motor vehicle drivers at gated railroad-highway grade crossings and behavioral modifications in response to installation of a centerline barrier that prevented drivers from going through the gates. A comparison of driver behavior in the pre- and postbarrier periods indicated the effectiveness of the barrier in reducing unsafe actions. A major concern of the Nebraska Department of Roads is the potential for crashes at railroad-highway grade crossings that result from unsafe actions of motorists such as rushing the gates to beat an oncoming train and playing "chicken" with an approaching train (i.e., intentionally standing a motor vehicle on the tracks and moving only when the train brakes). Some driver actions at crossings (e.g., backing up, U-turns) may result in crashes involving motor vehicles only. The railroad crossing at North 141st Street in Waverly, Nebraska, was studied for about 4 months with the help of a night vision camera and a digital video recorder. Motor vehicle driver behavior was observed when the gates were down, and unsafe actions were noted. To reduce gate rushing and other unsafe behaviors, a flexible rubber and plastic barrier was installed to prevent motorists from going through the gates. The postbarrier actions of motor vehicle drivers were monitored and compared with the preinstallation period by using appropriate statistical tools. The results provide interesting insights into how drivers modify their actions in response to physical changes at railroad crossings, in this case installation of a barrier along the street centerline. The barrier reduced some of the more dangerous types of driver actions such as gate rushes.