The reason why a "dutch" infrastructure will never work here is very simple....space. For whatever reason the original dutch city planners decided to built very wide streets (even before the advent of mass cycling and mass motoring), so squeezing in a couple of bike paths alongside the roads wasn't too hard, just shave a bit off the road width and a bit off the footpath.
Then look at somewhere like London, a medieval era city that's been ripped up and rebuilt over the years, but the street size remains mostly the same as it was. When the road is only wide enough for two cars and the pavement is already narrow, there's just no room for a segregated bike path. When we do have a new build town (ie Milton Keynes, Stevenage, Bracknell spring to mind), they can plan in the space from the start (these town aren't perfect, but much better than most in terms of cycling infrastructure).
In our older towns, unless you are advocating either banning cars or demolishing buildings...nothing's going to change. What they tend to do is just turn the footpath into shared use, and we all know how bad that can be. Personally I'd like to see restrictions on car use in urban areas and more use of park and ride schemes, but that would cause an almighty stink with BMW man.
Most older cities in the Netherlands have narrow streets and buildings directly adjoining pavements. In fact I think this may have been one of the reasons that they took a decision on promoting the bicycle - the town centres were simply becoming gridlocked with cars.
What the Netherlands does very well, and often gets missed, is that they control transit through these small streets, frequently reducing it to local access only, or even banning cars altogether. So where do the cars go? In many cities if you want to move from North to South you cannot go through the centre but have to use the bypass. Which extends the journey time by car significantly but stops the small streets being clogged with through traffic.
I think the segregated lanes are but a small part of the dutch system. They actually distinguish between roads - which are for transit, and streets which are local and shouldn't carry through traffic. And the street systems are made for the convenience of the pedestrian and cyclist as opposed to roads where modes may be segregated as they are designed for heavy traffic use. We can have as many cycle paths as we like, but we (or rather architects and town planners) have an attitude that every available piece of tarmac should be available for vehicle travel. Whilst this is the norm we won't get anywhere with putting in cycle lanes etc. Because the priority is motorised vehicle travel and everything else is secondary.
To see the effects of the views of those who plan and create our road systems, have a look at the Olympic area in Stratford. There, they had any amount of space (since it hadn't been defined) to create their road system and what do we end up with? Hugely wide roads with at least two lanes each way to carry local traffic going to Westfield, pavements which are isolated from either side of the road and a cycle way on said pavements which starts and stops and is completely disjointed. And this is what they manage when they have a
blank sheet of paper.
Half of the problem lies with those who design and build our urban environment. They are still busy modeling traffic flow when - at least in London - more and more people are starting to find other ways to travel because the policies are simply not working. Planners and architects are lagging, not leading, change and probably as big a part of the problem as anything else.