I think the idea of free white bicycles stems from an idea that started in Amsterdam in the 1960s - the bikes are available in a variety of sizes at the Visitor Centre and they are to be used to cycle through the national park - you can choose routes yourself or there are recommended routes. If you are unused to a bicycle as I was choose just to go to the Kroller Muller museum by bike. You leave your bike at your destination and then find it again or another one to go back to the Visitor Centre where the car park is.
Everyne knows that the bicycle is the national means of transport witin the Netherlands. Here per inhabitant one enjoys the most kilometres of bikingpaths in the world. We practically all have a bike and some even more then one (Irina and me have yet four, but if Ilja grows up and learns to drive a bike ... this number will grow).
The National Park the "Hoge Veluwe" has many good maintained bikinglanes going through the various landscapes within the park. As they lead away from the roads that cars use, one feels like becoming one with nature (that is ... if it's not a too busy day, otherwise you might here "tring-tring" behind you several times (-: ).