| Abstrakt: |
Road Authorities in Australia provide a range of road signs, the type, size, placement and manufacture of which is covered by a range of Australian Standards, Design Manuals, and Codes of Practice associated with legislation. However the in-service performance is not currently mandated. Within their Road Asset Management plans, road authorities must describe their road-related services and intervention levels for service provision, as the basis for budgeting, community acceptance and defence of liability claims. Signs must remain visible and legible at distances assumed by design engineers when initially installed, by day and by night. The quantification of in-service night-time visibility and legibility standards applicable to individual signs or even classes of signs is particularly difficult, with multiple, varying factors to take into account in any given circumstance. However, research has determined rules of thumb that can be applied (albeit simplistically) as de facto performance standards, and in-service performance can be assessed against the resulting criteria. A key component of the assessment process is determining a sign΄s `retrore flectivity΄ (or reflective luminance). The issues associated with measuring retroreflectivity against objective service standards is discussed in detail, as well as presentation of a regional municipal road authority΄s recently adopted approach. [ABSTRACT FROM AUTHOR] |
