Authorities said the driver of a Missouri Department of Transportation vehicle was struck and killed while shutting down Interstate 70 in suburban Kansas City after an earlier fatal crash. Clifton J. Scott, 50, who was helping authorities shut down traffic along Interstate 70 following a four-vehicle accident in the eastbound lanes near Lee’s Summit Road. The motorist-assist driver was hit outside his vehicle and died at the scene. Motor-assist drivers patrol major roadways, and their duties include helping with traffic control.