It is assumed that a decrease of CO2 will lead to a decline of the greenhouse effect. One way to obtain this effect is by laying out more forests, which results in a growing supply of homegrown construction wood. In order to link this increased supply to a demand, Rijkswaterstaat asked Zwarts & Jansma to investigate whether wooden freeway signs are a possible solution.
Thus, we designed a frame, which consists of trapezium-formed laminated joists, glued together with the help of a vacuum technique to form a tube. The gantry signs have a maximum span of 45 metres. In march 1999 the first prototypes were placed in Brabant.In 2002 more were placed on highway 9 near Alkmaar.