I wondered that at the Bicycle Culture by Design lecture. Are cyclists in Europe just displaced walkers?
I seem to deal with families who are active anyway and are wanting to increase their use of human power - initially for getting round town but often that escalates to longer tours! If there was nowhere to cycle many of these would walk I reckon. Common for mum and dad to walk with kid on scooter or pavement bike around town. Often see adults cycling on pavement with heir kids in tow too so for them it is a kind of walking experience.
Biking in Amsterdam and Copenhagen is akin to walking as MCA says.
Looking at centre of Edinburgh on Sunday when MCA was about to leave I saw about ten bikes in half an hour, hundreds of people walking and a lot of cars with one person in them. The High St is just a mass of people and anyone on a bike would have problem getting through. At the Hub the road is open to traffic but people just walk over it due to volume of numbers.
Our transport balance is of course disturbed by the fact the public transport system is infrequent on Sunday and parking is free (often using bike and bus lanes).
During the week we seem to have cyclists in survival mode and i wondered whether the lack of these cyclists on a Sunday was that our hard core need time off?!