The objective of this project is to improve the safety performance of roadsides by investigating the effectiveness of: * protecting against impacts with roadside hazards, e.g. trees or critical slope embankments, through selection of clear zones; * providing more forgiving roadside hazards, such as frangible poles; * safety barrier selection and placement; * retrofitting of safety barriers for improved motorcycle safety. The project will provide input into future revisions of road and roadside design guidelines. This Stage 2 interim report presents the project findings achieved during 2009-10 financial year. The agreed scope of work consisted of preliminary investigation of the fundamental links between clear zones and crash outcomes, and of the key parameters influencing selection of clear zones. Analysis of the role of shoulders (sealed and unsealed) in the likelihood of run-off-road crashes was undertaken. Also, the general effect of different roadside surfaces on slowing down errant vehicles was investigated. Preliminary analysis of crashes into different roadside hazards was undertaken to better understand the effects of these hazards on crash severity. This led to investigation of the substitution of certain roadside hazards with frangible options (e.g. poles, posts). Finally, a preliminary analytical investigation was undertaken of the in-service performance (severity) of different safety barrier types. The influence of their offset from traffic was investigated for a broad sample of roads. The report also documents the input of Austroads stakeholders into the research directions and methods for Stages 2, 3 and 4. (Author/publisher)
Samenvatting