To get right to the point of my opinion regarding design and planning between the US and Dutch, they are complete and polar opposites. The US is placing motor vehicles at a higher regard than the cyclists. The movement of vehicular cyclists (VC) in my opinion is absurd. Where on the other hand, the Netherlands treats the two modes of transportation as separate entities when designing and planning for bikes.
In the United States, John Forester has been a driving force among planners to have cyclists ride amongst cars. He believes that separating the two modes, as in the Netherlands, is more dangerous than combining them, as widely used in the US. This is done with sharrows and bike lines with vehicular traffic. To put a couple visuals to what combining a vehicles and cyclists together equates to; a roughly 4,000-pound object moving up to 40 mph within 3 feet of 225-pound object moving 10 mph. Another example is a small airplane taking off three feet from an interstate and stating it is safer. In the Netherlands this is unheard of, the safety of the cyclist comes first. A cyclist is vulnerable compared to a vehicle and they know this and teach this from grade school to driver training on how to avoid endangering cyclists as well as pedestrians. In the Netherlands the society wants the benefits of bike infrastructure, even the vehicle owners. Where as in the US it seems as if only a small percentage of the population want to increase this infrastructure since most of the population is car centric.
With different mindsets, design and planning are affected. The US is starting to see this slowly but it is better late than never. Trying to separate these two modes of transportation helps when the public knows the facts about the current ideology has dominated the design and planning in the US. The main impact this affects are injuries and fatalities among cyclists. When comparing the US and the Netherlands the numbers US is off the chart.