A "thinking road surface"
Dick de Waard, Karel A. Brookhuis, Magrita C. Noordmans, Jeroen H. Hogema, & Rob M. Visscher
Extra to paper in D. de Waard, K.A. Brookhuis, and C.M. Weikert (Eds.) (2004), Human Factors in Design (pp. 83 - 94). Maastricht, the Netherlands: Shaker Publishing.

Figure 1. Screenshot of the LED lightbar as seen in the driving simulation.

Figure 2. Denkdek simulated in the driving simulator of the University of Groningen

Figure 3: Control panel of Denkdek.

Figure 4: Close up control panel of Denkdek.

Figure 5: Denkdek implemented on the A9 motorway.

Figure 6: Denkdek on the A9 motorway.
Denkdek has been removed from the A9 motorway, but there is still a lot of information (including some movies) on http://www.denkdek.nl.