The advantage of cycling. You could probably outrun a T. Rex if needed. http://news.bbc.co.uk/1/hi/sci/tech/6956867.stm Apparently it had a top running speed of 18mph. Many a cyclist can out do that on short distances at least. Mind you... stick a T. Rex on a nice carbon time trial machine and we'd be b*gg*red... well, eaten anyhow.