Tiny glass beads embedded in the road marking material reflect the light from headlights in dark or wet conditions. This is why the markings are still so easy to see in the dark, the fog and the rain. Thanks to their structure, the lines and surfaces are extremely durable as well.
Various systems can be used to apply these kinds of structured, three-dimensional markings to roads. One of these is cold-plastic marking based on Degaroute reaction resin from Evonik Industries. Degaroute has proven itself in this application for more than 50 years, the quality of the product having long produced impressive results. Lately, however, it is not just safety but the environmental aspect that is playing a more important role. Increasing traffic volumes call for more and more markings—but not at the expense of the environment.
For this reason, Evonik compared its Degaroute-based road markings with three other common road marking systems: hot-spray plastic, solvent-based paint and water-based paint. The specialty chemicals company studied all four systems as part of a comprehensive life cycle assessment (LCA). An LCA is a systematic tool that analyzes the influence a product has on the environment over its entire lifespan. It takes account of the entire value-added chain, from the raw materials, through production and application, to disposal or recycling.
In this case, Evonik studied a two-lane, one-kilometer section of roadway equipped with a middle stripe and two edge stripes. The assessment period was ten years—after this time roads normally have to be resurfaced. Depending on the technology used, the markings have to be renewed at different times in this period.
According to the results of the LCA study, cold-spray plastic with Degaroute is far superior to the other technologies. It obtained the best results, thanks to its longevity in particular. The study showed that, more than anything, the service life of a marking is key to its environmental impact. And in this respect, the solvent- and water-based systems came off second-best. Over the period of the study, the solvent-based paint had to be reapplied ten times to obtain the marking, while Degaroute-based cold-spray plastic had to be reapplied four times. Hot- spray plastic did similarly well in terms of longevity, but it consumed more material.
This high durability is primarily a result of the glass beads contained in the marking material. According to the LCA study, durability is also the deciding factor for CO2 emissions and, therefore, the global warming potential of the individual systems. Hot-spray plastic has a 50 percent higher warming potential than Degaroute-based cold-spray plastic with glass beads, and paint systems are roughly 80 percent higher. In comparison, the application step accounts for a small percentage of the global warming potential—with the exception of hot-spray plastic, which has to be applied in a melted state at high temperatures, and requires the use of gas burners.
The LCA study was conducted in accordance with ISO 14040 and critically reviewed by independent experts from industry, science and research. In early 2012, the system was certified to ISO 1404