It wasn't a design flaw. It was over used. Well, I guess it was a design flaw considering it wasn't designed for that many cars. I found out that bridge was meant to handle 40,000 cars per day maximum. When it was built only 12,000 cars per day used it. At the end over 200,000 cars used it per day. Not only that but it was being resurfaced. My street was resurfaced a couple years ago and let me tell you it VIBRATES. Back during the civil war soldiers staggered their marches over bridges as to not create a consistent vibration. Resurfacing is a consistent vibration with heavy machinery. Oh, I forgot to mention there was a 20ft pile of sand sitting on one side of the bridge. That bridge should have been replaced back in the 90s when its daily traffic went over 40,000, period.