You can read an in-depth description of The White Road in Playground Worlds 2008 (PDF) p.102.

Credits
Designers and participants: Troels Barkholt-Spangsbo, Pia Basballe, Kristin Hammerås, Lars Munck, Bjarke Pedersen , Linda Udby.
Location: The road between Copenhagen and Frederiksund, Denmark.
Date: September 8.-10. 2006