For reasons of road safety Highways England requires that the condition of road markings and reflective road studs be monitored on a ‘frequent’ basis on the strategic road network. The current standard, TD 26, states that road markings shall be routinely inspected in order to identify when the deterioration is such that a reduction in the delivery of safety benefits could result. To avoid the need for lane closures it is desirable for assessments of road marking condition to be carried out at traffic-speed. Therefore the measurement of the retro-reflectivity (or night-time visibility) of longitudinal markings, was introduced to Highways England’s TRACS2 (TRAffic-speed Condition Survey 2) network survey of road surface condition in 2008. The TRACS2 survey experienced problems with the network level measurement of the retro-reflectivity of road markings when attempting to utilise the standard equipment available at the time (Ecodyn). Therefore a research programme was commissioned by Highways England to identify and develop an improved approach to the measurement of retro-reflectivity of road markings. The programme had the longer term aim of demonstrating a practical method to deliver improved measurements of road marking retro-reflectivity, so that Highways England could re-introduce this measurement into the TRACS survey with confidence that the survey would be capable of delivering accurate and consistent information on the condition of road markings. (Author/publisher)
Samenvatting