'Familes on the Brink:' Elderly Drivers Balance Independence and Safety

Robert Hill and his daughter Cathy McArthur are in the midst of a classically fierce clash. Like many Americans with aging parents, McArthur doesn't think it's safe for her 84-year-old father, who has Parkinson's disease, to drive anymore. Watch 'World News With Diane Sawyer' for more on this story tonight on ABC at 6:30 p.m. ET "We have a disagreement. If it doesn't go away, and I'm not able to drive, I will leave the country," said Hill. "I'll go to a country where they don't have driver's...Full Story