I can personally attest to the effectiveness of those Dutch Intersections. My wife and I - who are both very mediocre bicyclists - completed a 12-day bicycle tour of Belgium and Netherlands (Bruges to Amsterdam) in this past September without becoming hood ornaments.
The traffic separation between car and bicycle was pretty much bulletproof. Big cities, small towns - it didn't matter - the street engineering was safe and effective in spite of the dense population.
Our bicycle tour group of 20 (many of whom were worse bicyclists than us) was always in safety. Wish it was so here.
I think that one or two of our traffic engineering types should be sent on a bike/car/rail tour of these countries. Also, in addition to the Dutch intersections, they use traffic circles all over the place and it helps car traffic flow.
Paul McGown, Burnaby