A friend of mine and local bike blogger just completed 150,000 miles by bike. He commutes via bike everyday and rides about 6,000 miles/year. He doesn't race but just rides for the enjoyment. The last time he drove a car to work was 1997.
http://bikenazi.blogspot.com/2012/12/my-150k-day.html
http://bikenazi.blogspot.com/2012/12/my-150k-day.html