The story:

Big Ben in serious condition after motorcycle accident

Interestingly, check out this May 2005 interview:

ESPN: How much do you view riding a motorcycle as a risk?

Roethlisberger: I think it can be a risk. It depends on how you ride. I don't ride a sport bike. If I'm riding a sport bike and trying to do tricks, and going 200 miles down the highway, that's probably pretty stupid. But when you're riding a Harley or a chopper and you're riding with a group of people and you're not on the highway and you're cruising, you're relaxing. I don't think its as much of a risk as people make it out to be.
Levastire shared this quote:

Roethlisberger was between radio interviews and on his black 2005 Suzuki Hayabusa -- large, racing-style bike -- and heading toward an intersection on the edge of downtown. A silver Chrysler New Yorker traveling in the opposite direction took a left turn and collided with the motorcycle, and Roethlisberger was thrown, police said. The other car was driven by a 62-year-old woman, police said. They didn't immediately release her name and no charges were filed.
I guess he got bored with Harleys. So much for safety.