This weekend members and supporters of Mothers Against Drunk Driving will be tying one on. MADD Polk County chapter president Bill Shackelford explains they’ll put red ribbons on car antennas to remind motorists to drive safely during the upcoming holiday season. It’s one of many strategies to raise awareness, at hundreds of chapters nationwide. Shackelford says MADD began nationally in 1980 and within a few years the first Iowa chapter was organized.He recently realized the chapter began a campaign over a decade ago to have legal drunk-driving defined as point-oh-nine percent blood alcohol, a move that hasn’t been passed yet, but the group’s been around about fifteen years.