So I crashed my bike about a month ago. I decided to, finally, share my experience. I was riding in the Wilmington Gran Fondo. It was drizzling and raining off and on. Due to the rain and the effect it had on the street markers, I believe, I found myself about 15 miles off the course. I was now lost in Kennett Square, Pennsylvania, the ride was in Delaware, yes, I was so lost I was in another state. OK, anyway, after getting some directions from a local I began to make my way back to the finish line. I was told I would go over a bridge and then I should make a right shortly thereafter. I never made it to the turn. Ripping down a slight hill I turned slightly to the left and saw the bridge, the METAL GRATE BRIDGE, and not enough time to stop. I had racing slicks on, so once I hit the metal grating my bike got super squirrelly underneath me. I maintained "control" over the bridge, but once I hit the transition back to asphalt my wheel was cocked left, causing me to roll the entire bike onto my right hand and arm. My right hand pinky was completely opened up to the bone, and the ligament was ripped off. My ring finger was also opened up, I could see my ligament moving when I flexed it. I barely missed flipping over the kneeling wall on the side of the bridge. So, I am very lucky. A passing motorist called an ambulance and my wife while I held my finger together. I wound up having a piece of my wrist ligament grafted onto my pinky. The wounds have just healed. I am currently going through PT to regain flexibility in my pinky and ring finger.
So....with all that said, let me give everyone one piece of advice. If you are unsure about a bridge's surface, STOP. Get off your bike, and WALK YOUR BIKE ACROSS BRIDGES.
I know it's lame, but it could save you a lot of pain.