Road markings ? cosmetic or crucial?
Keywords: Road Environment
Submission Date: 2003
Horizontal painted pavement marking materials are applied to road surfaces to provide safe guidance for the travelling road user public. These markings need to function both day and night, wet and dry, to provide safe guidance and clear signals at a consistent level while presenting a preview of the forward road geometry. Such delineation systems may create a potential hazard if the differential friction between the marking and the pavement exists, particularly for cyclists and motorcyclists.
Potters Industries, having the luxury of a dedicated purpose built R&D application test vehicle (The DART) and the luxury of suitable test deck areas, has taken the initiative in developing safer systems and generating data to assist the pavement marking industry. These trials have been partnered by RTA?s Scientific Services Branch. Requirements for Performance Based Contracts for pavement markings are fast approaching, with little data to assist the specifying engineer on realistic intervention levels that can deliver safe performance outcomes. These ?safe outcomes? should include minimum levels in dry night visibility, wet night visibility and skid resistance for both transverse and longitudinal pavement markings, throughout the life of these markings.
To provide the anticipated levels of skid resistance, usually requires a surface application of angular particles. These angular particles may create shadows over the surface applied glass beads and render the line invisible during night conditions. The challenge has been to find a balance between angular and spherical surface applied particles, in size, quality, quantity, ratio and method of application, that can provide durable cost effective horizontal pavement markings with excellent dry night delineation, excellent wet night delineation and a high level of skid resistance.