The Concord Road covered bridge warning structure got a makeover today! Cobb DOT crews installed new rubber ballads to replace the polyvinyl chloride (pvc) pipes used in the original structure. The new rubber material is more resistant to weather conditions and not quite as rigid as pvc, which can become brittle in freezing temperatures and crack easily when vehicles strike them.  By contrast, the new ballads are designed to take a beating and are often used in school zone crossings as a "flexible" traffic barrier that can be run over and still bounce back.