Having lived in Japan for several years, I can tell you one thing - there may not be formal segregation, but most people - with the exception of roadies like me - cycle on the pavement along with pedestrians and at very low speeds, given the chance. This and the culture of politeness on the roads has more to do with the low number of deaths and injuries in Japan than the number of cyclists per se.
I've lived there too and my experience is different. If you are in busy downtown Tokyo or Osaka during the day then cyclists are rare and tend to be on the pavement going slowly as pedestrians on wheels (and there also the culture of politeness prevails). But out in the suburbs especially during the morning and evening commute to the station but also during the day out in the suburbs they ride on the roads IME not least because the pavements are clogged with pedestrians walking to the station and are too slow. I've done a lot of transport and leisure cycling with Japanese friends cycling to the station or with the family or to friends/relatives houses and it was almost all on the roads and quite undisciplined as was all our cycling with them out in the countryside from family outings to road rides.
However, having cycled in many countries around the world, including the Netherlands, Britain does not come off well in comparison. Sure, if you are an experienced cyclist who enjoys the kind of insanity in London, it's okay, but that will never, ever, generate a real critical mass of cyclists, or mean than Joe or Jane Ford will decide to take a bike and not the car for shorter trips - which is what happens in the Netherlands, Denmark or even Germany. <......> Frankly cyclists like us are not best placed to understand people who wouldn't considering cycling at the moment and therefore think of appropriate ways to make them do so.
London is quite different and the availability of Boris Bikes is really changing it dramatically IMO and making people realise that anyone can cycle. There are many people of all sorts cycling now and the morning and evening rush hour roads are packed with cyclists. Cambridge is similar and always has been. I think there are a couple of factors. When cycling is seem as normal, people don't mind doing it. When its seen as the pastime of lycra clad road warriors risking their lives they shun getting involved. This is covered quite well in
Fear of Cycling by David Horton, a sociologist from Lancaster University (his summary article on
Copenhagenize is an interesting read too and highly relevant to this issue). The Dutch in general are not fearful of cycling, of being seen as different if they cycle and they don't promote cycling as something to be feared as we do in the UK.
An interesting second element IMO which you see in London particularly now (and if you drive in London or Cambridge you can experience it from the driver's side) is when there are large numbers of cyclists swarming through traffic it can be quite disconcerting for a driver and lead to anger and conflict seen at its extreme in some of the critical mass incidents. Its exacerbated by the impotence of being stuck in traffic and seeing all these people swarming past you making progress you can't or worse, appearing to slow your progress. To a large extent the segregated facilities in the Netherlands avoid this conflict by removing the bikes from the cars and cars from city centres. If you have ever tried to cycle on the road when there is a segregated facility in the Netherlands, the drivers make it very clear that you should not be there and if you cycle in the facilities you have to be prepared to go at the speed of the herd which can be quite slow and that of the slowest. And if you try to drive in the city centres you get to feel very much like an interloper much of the time.
But personally I think the secret in the UK is to make it so that cycling is seen as a normal activity that normal people do in normal clothes on normal roads and normal bikes and not the preserve of a breed apart. That is what the Netherlands has achieved while we do our best to do the opposite. It really is quite phenomenal to see what Boris Bikes have done for cycling in London even though they are a minor part of the scene (about 5% of journeys). But they are visible and visibly used by normal people sans helmets and in normal clothes making people think "I could do that" and often getting their own bike out the back of the garage.
