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Wed, 08-September-2010

Bright Lines of Safety
11 May 2004

Every driver appreciates bright white road markings that show the way, both during day and at night-time. Road markings offer the best guidance to drivers, particularly in the dark. Safety markings (profiled or textured markings) are characterised by different kinds of raised structures, one of many companies that provide a wide variety of such markings.

"If professionally applied and correctly selected, such marking materials offer a range of interesting and extremely useful properties to road users."

For example, textured markings function according to the following principle, says Degussa.

Cold plastics offer symbols/directional arrows, pedestrian crossings and horizontal markings

"In classical road markings, glass beads are used to achieve retroreflection of the light from vehicle headlamps. The correct embedding of the glass beads in the liquid marking material during application is crucial for good, bright retroreflection.

"If the glass beads are covered with a film of rainwater, however, this principle ceases to function. Headlamp light is no longer reflected toward the driver, but is reflected as by a mirror, according to the well-known physical law for light rays, the angle of incidence is equal to the angle of emergence.' This means that centre lines of this type remain largely invisible to drivers at night and in wet weather.

"However, if the glass beads are incorporated in a raised position on a specially textured marking, though, retroreflection is ensured even in the presence of rainwater" adds the company.

Various types of raised effects are conceivable in a more or less regular form, says Degaroute, which points to profiled and agglomerate markings.

Marking for bike paths, bus lanes and pedestrian areas

"The retroreflection in wet weather based on three-dimensional causes has considerable effects on the visibility of a road marking. The textured marking with agglomerates is particularly worth mention. This is a 'random' textured marking applied by means of special techniques."

This special technology invented about ten years ago in Switzerland is said to provide excellent night-time visibility in wet weather.

Degaroute from Röhm GmbH & Co, a subsidiary of Degussa, offers permanent cold plastic markings manufactured from rapidly curing two-component reactive resins based on methacrylates, and are said to offer a variety of potential applications in the form of thick-layer, thin-layer, profiled or textured markings.

The company says that liquid Degaroute resins are always processed together with fillers and pigments, and their flow can be adjusted to a wide variety of formulations and processing methods, such as extrusion or spraying. Their chemical composition makes it possible to adjust them to various degrees of hardness, allowing their use on different substrates such as asphalt or concrete, in all climate zones.

The markings can be applied manually using draw boxes, manual marking machines with special drawing devices or extrusion machines, and the layer thickness may be between 1.5 and 3mm, and from 0.3 to 1.2mm in the case of cold spray plastics

Published in World Highways, April 2004 (Road Markings)

.: Bright Lines of Safety 11 May 2004
.: Traffic Management 27 March 2004

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