Motorcycle crashes are a significant contributor to deaths and serious injury on our roads. As outlined in the Australian Transport Council’s National Road Safety Strategy, in Australia, motorcycle riders made up 16% of all fatalities in 2012, and 22% of serious injury casualties despite representing only a very small percentage of total traffic volume (one per cent of vehicle kilometres travelled (VKT)). The rate of motorcyclist deaths per registered motorcycles is five times higher than the rate of occupant deaths per registered 4-wheeled vehicles. In recent years a clear upward trend in motorcycle crashes was identified in Australia and New Zealand. This report highlights the relationship between motorcycle crashes and road infrastructure, and specifically, how road infrastructure influences both the likelihood of a crash occurring or the resulting severity of a crash. The investigation included: a comprehensive literature review, crash analysis, the identification of road infrastructure elements as crash factors, the identification of effective mitigation measures and their likely safety benefit and consultations with stakeholders. The objectives of the project were to: * determine the influence of road infrastructure elements in motorcycle-related crashes, and * identify countermeasures that have the potential to reduce the incidence and/or severity of such crashes. Road infrastructure elements considered included design parameters (e.g. horizontal alignment, super-elevation), road surface condition (including skid resistance), roadside hazards and overall maintenance condition. The project is focused on providing guidance to practitioners, including a number of recommended updates to the Austroads Guides to Road Design, Traffic Management, Road Safety and Asset Management, some of these updates can be drawn directly from this report and some will need to be further researched before being changed within the Guides. It is also hoped that the project will contribute to several of the objectives within the Australian National Road Safety Strategy 2011-2020, including safety improvements on popular motorcycle routes (a specific action for the first three years of the strategy) and providing advice ahead of plans to introduce motorcycle black spot/black length programs in all jurisdictions (a ‘future’ action). A literature review of national and international guides, publications and research papers demonstrated that guidance of road infrastructure elements that adversely affect motorcycle crash risk is available, however this is not comprehensive enough for a practitioner to make engineering decisions considering risk, cost and benefit. A crash analysis was undertaken to demonstrate the relationship between motorcycle crashes, travel purpose period, vehicle configuration (i.e. motorcycle only and multiple vehicle crashes involving a motorcycle), road geometry, road layout (e.g. intersection type) and crash types. For comparative purposes, vehicle crashes at the same location were also analysed. This demonstrated that motorcycle crashes are effected by travel purpose period, with a majority of motorcycle crashes occurring during the week. Explanations of why, and how, road infrastructure elements influence motorcycle crash risk were researched and are provided. This primarily involved identifying how the design and condition of road infrastructure elements can influence either the likelihood of a crash occurring or the resulting severity of a crash. Where a number of elements that would increase the likelihood or severity of a crash were present concurrently, the proportionate increase in risk was demonstrated using the AusRAP model. The report has built up a compendium of treatments, presented and explained in such a way that engineering decisions to manage these elements can be justified, even if outside of existing design warrants, and asset management and maintenance practice. The report highlights that motorcycles should be identified as an individual road user group and considered as a ‘design vehicle’ during road design and asset management and maintenance practices. It is concluded that motorcycle crash risk can be managed, remedial treatments have been shown to be affective, however changes in practice are required in road design, asset management funding and routine maintenance performance contracts to proactively manage motorcycle crash risk. One example is in the specific identification of road sections and/or routes that pose the highest crash risk to motorcyclists, so that they can be managed and maintained appropriately. In addition, the author advocates proactive motorcycle specific network safety assessments and road safety audits, as well as fine tuning in design parameters for roads carrying significant volumes of motorcyclists (e.g. horizontal geometry, sight lines, lane and shoulder width, intersection types, intersection quality and controls). It is also encouraged that the range and detail of mitigation measures be expanded. (Author/publisher)
Samenvatting