DIRTcar Summer Nationals officials cancelled Wednesday's 30-lap, $5,000-to-win 16th round at Benton (Mo.) Speedway because of rain and thunderstorms in the area. The event won't be rescheduled.

Series competitors will head to Thursday's $5,000-to-win event at Riverside International Speedway, the tour's first visit to the West Memphis, Ark., oval.