Here's a YouTube video of a cyclist crossing the St. Nazaire bridge over the Loire estuary. It's pretty hairy. He gets to the beginning of the bridge at about 0:40 seconds. Around the 4 minute mark, it starts to get pretty bad. You can hear the wind and the guy is wobbling a bit. He pauses when he gets to the middle of the bridge, around the 9 minute mark. I didn't watch the rest.