I suspect I'd die long before I'd racked up 29 million km ;-) Have only had one accident whilst commuting by bike for the past four years, and that was my mistake when navigating through traffic crawling along at ~5mph (although I've also fallen off twice on my way home from the pub, and about a third of the times I've been out mountainbiking, but there was no traffic anywhere near in those cases :-) I agree that the benefits far outweigh the possible problems.