The Dutch Ministry of Infrastructure and Water Management, Rijkswaterstaat, is starting an experiment with 24 ‘plant-based’ traffic signs along the A58 near Oirschot.

Rijkswaterstaat wants to test whether these so-called ‘bio-signs’ can be an alternative to the existing aluminum traffic signs. The signboards are made from hemp, sugar waste, and vegetable oil.

Real outdoor conditions

The 24 signboards will be tested for a year in real outdoor conditions (weather, UV, wear) in the test site near Oirschot. Based on the results, Rijkswaterstaat and other authorities can determine whether the reusable, biobased traffic signs are suitable for use on a larger scale in the future.

Every year, enormous numbers of traffic signs are produced in Europe, almost always made of aluminum and fossil-based plastics. The Dutch believe this can be done more sustainably. 

They collaborated with Plantics on the project. The signs themselves are made from raw materials sourced in the Netherlands, including hemp from Oirschot and Groningen. The hemp is combined with a biological resin derived from residual streams of the sugar industry and from vegetable oil production.

Fully circular

Compared to aluminum signs, hemp stores CO₂ while growing, and its production is far less energy-intensive. As a result, the signboards are fully circular. This allows the materials from old signs to be separated again through sustainable recycling.

That material can then be used for new traffic signs or other applications. And when such a signboard ends up in nature, after a collision, for example, the biomaterial breaks down naturally in the soil.

Other applications

The bio-based signboards are not an entirely new idea. Hemp and flax composites are already used in automotive interiors and construction materials. But traffic sign applications are still rare. Sweden developed biobased traffic signs using lignin resin and fibers.

Other sectors also experiment with bio-based materials, such as bioasphalt and wooden or bamboo street furniture. The idea of using biodegradable materials for traffic signs is innovative and sustainable.

After all, traffic signs are produced in huge quantities every year, and their production is very energy-intensive. The new signboards could become a new standard across Europe.

The Netherlands alone has about 6 million traffic signs, with about 300,000 replaced every year.