Prioritisation of guard rail remediation works

Abstract

Road Safety Barrier Systems standards have changed over time. Consequently most road authorities have a variety of barrier systems within their jurisdiction and difficulties may be experienced in determining which sub-standard barriers create the greatest risk. This project, conducted in association with the Southern District of the Department of Main Roads, Queensland, sought to determine a method for prioritising remedial works on sub-standard barriers. The project is focused upon the local authority areas of Esk, Gatton and Laidley. A review of design standards and strategies employed and proposed by other state and overseas road authorities was performed. Further work developed a prioritisation method by which remedial works can be programmed upon federal, state and local government controlled roads. The developed prioritisation method uses an assessment tool to evaluate individual guardrail sections against 3 specified criteria: traffic volume, traffic composition and guardrail standard. It is imperative to bear in mind that the developed procedure is a tool and that results must be executed in conjunction with good engineering judgement. Key findings of the project were: - It is advantageous to have crash barrier data held by the road authority in a single, regularly updated database; - Significant variations in traffic volume and/or composition along a length of road need to be discerned if an accurate assessment of variations in risk are to be calculated; - The study has found a high priority should be given to locations where guard rail is no longer required or a roadside hazard can be removed or reduced; and - The financial implications of retrofitting all non compliant guardrail in the Southern District of the Department of Main Roads are significant.