The Times recently reported on a 67 year old Englishman, Mike Roots, who has been "cycling the world" from his exercise bicycle. Since 1996 he has covered 80000 miles.
He's not cycling it for real on the roads because they are "too dangerous."
It's a glimpse into the problems facing many people in the UK who would like to cycle, but do not. A feeling that the roads are too dangerous is not irrational, but quite understandable in a country where cyclists simply are not provided for.
This is perhaps a good example of a lack of subjective safety preventing someone from cycling.
What Mike is doing may seem strange, and some of the readers responses to the article are quite funny. However, I think it's good that Mike is raising the issue of subjective safety.
By way of contrast, Dutch people of pensionable age make a quarter of their journeys by bicycle.
Now for a real ride around the world... James Bowthorpe from London just took the world record for riding right around the world by bike. There's a TV interview here.
Thanks to the Crap Waltham Forest blog for the story.