Towards Safe System Infrastructure a Compendium of Current Knowledge
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Research Report AP-R560-18 Towards Safe System Infrastructure A Compendium of Current Knowledge Towards Safe System Infrastructure: A Compendium of Current Knowledge Prepared by Publisher Jeremy Woolley, Chris Stokes, Blair Turner, Chris Jurewicz Austroads Ltd. Level 9, 287 Elizabeth Street Sydney NSW 2000 Australia Project Manager Phone: +61 2 8265 3300 austroads@austroads.com.au Colin Brodie www.austroads.com.au Abstract About Austroads This report provides a compendium of knowledge on Safe System Austroads is the peak organisation of Australasian road treatments and identifies real world experience in the practical transport and traffic agencies. application of solutions that can mitigate crash severity. Austroads’ purpose is to support our member organisations to The Safe System is internationally regarded as the best practice deliver an improved Australasian road transport network. To approach to road safety. Although Australia and New Zealand have succeed in this task, we undertake leading-edge road and been early adopters of the approach since 2004, there has generally transport research which underpins our input to policy been a lack of clarity amongst practitioners on how best to integrate development and published guidance on the design, the approach into their daily activities. construction and management of the road network and its associated infrastructure. Assessment frameworks and tools are also now emerging that allow the alignment with Safe System be better quantified. A hierarchy of Austroads provides a collective approach that delivers value treatments is described that provide practitioners with a basic for money, encourages shared knowledge and drives understanding of the types of practices that should now be applied on consistency for road users. a trajectory towards a Safe System. Primary treatments are capable of virtually eliminating death and injury and certain supporting Austroads is governed by a Board consisting of senior treatments can transform the network a step closer to reducing the executive representatives from each of its eleven member overall harm being caused. organisations: • Roads and Maritime Services New South Wales • Roads Corporation Victoria Keywords • Queensland Department of Transport and Main Roads Road safety, Safe System, harm minimisation, error tolerant roads, • Main Roads Western Australia road design, traffic management, transport planning, urban planning • Department of Planning, Transport and Infrastructure South Australia ISBN 978-1-925671-28-5 • Department of State Growth Tasmania Austroads Project No. SS2016 • Department of Infrastructure, Planning and Logistics Northern Territory Austroads Publication No. AP-R560-18 • Transport Canberra and City Services Directorate, Publication date March 2018 Australian Capital Territory Pages 154 • Australian Government Department of Infrastructure, Regional Development and Cities • Australian Local Government Association © Austroads 2018 • New Zealand Transport Agency. This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without the prior written permission of Austroads. Acknowledgements The authors would like to acknowledge the support, encouragement, correspondence and feedback offered by practitioners in the compilation of this guide and in particular the discussions held as part of the SS2061 Safe System Infrastructure workshops held throughout Australia and New Zealand during 2016. This report has been prepared for Austroads as part of its work to promote improved Australian and New Zealand transport outcomes by providing expert technical input on road and road transport issues. Individual road agencies will determine their response to this report following consideration of their legislative or administrative arrangements, available funding, as well as local circumstances and priorities. Austroads believes this publication to be correct at the time of printing and does not accept responsibility for any consequences arising from the use of information herein. Readers should rely on their own skill and judgement to apply information to particular issues. Towards Safe System Infrastructure: A Compendium of Current Knowledge Summary The Safe System approach is regarded as international best practice in road safety and provides an outcome whereby death and serious injury are virtually eliminated amongst users of the road system. Safe System is the management and design of the road system such that impact energy on the human body is firstly avoided or secondly managed at tolerable levels by manipulating speed, mass and crash angles to reduce crash injury severity. The purpose of this report is to create a compendium of present Safe System knowledge and research in regards to planning, designing and managing roads and roadsides. It will provide a useful resource document that highlights the suite of well performing Safe System treatments developed to date. The Safe System model is described in several publications and it is common for individuals to be able to identify key components and the underlying core principles. However, what is not well understood is that the Safe System entails a harm reduction approach to safety. That is, planning, road design and traffic management needs to also consider how to reduce the severity of crashes when they occur. Why is this a better response than conventional approaches? Primarily, the understanding of what lies behind road user error is evolving but it is evident that many of the situations people are placed in when using the road system invite certain errors to be made. We now understand that many of these errors cannot be easily eliminated. Furthermore, system designers and managers have a responsibility to not only mitigate for predictable errors but also protect those innocently caught up in crashes. The appropriate response to dealing with this issue is to ensure that the road network is forgiving of error and does not allow people to inadvertently cause harm. Speed is at the heart of a Safe System and aspirational design speeds include: 30 km/h (car vs pedestrian/cyclist), 50 km/h (car vs car side impact at 90 degrees) and 70 km/h (car vs car head-on). With intersections, harm is mostly associated with red light running and unprotected right turns. Design options are to manage speeds to survivable levels and reduce impact angles. If 90 degree cross road geometry cannot be changed, further safety treatments such as speed plateaus on approaches can compensate for the non- favourable configuration. Where the intersecting approach geometry can be modified, designs that achieve lower speeds and impact angles will reduce the harm. The roundabout is a design that follows these principles but other innovative intersection designs are emerging. Signalised intersections should no longer be regarded as a primary treatment and compensating treatments are required to improve crash survivability. With high speed lane departures on rural roads, harm is being caused in interactions with the roadside (even when clear zones are present) or in head-on collisions. Protected corridors using continuous lengths of flexible barrier have been proven to dramatically reduce injury; in many locations centre barrier has virtually eliminated death from head-on collisions and lane departures to the right. These configurations outperform unprotected corridors that utilise the clear zone / hazard protection approach. Vulnerable road users require a low speed environment to interact with traffic. If this cannot be achieved then segregation must be used. There is guidance available regarding Safe System bicycle infrastructure design for Australia inspired by European practices. It is still not clear how motorcycles and heavy vehicles can be catered for in the Safe System. Infrastructure solutions must be combined with speed management and vehicle technology to achieve safer outcomes. Vehicle technologies have the potential to significantly reduce death and injury on the road network especially in relation to road departure and intersection crashes. Accelerating the deployment of these technologies in the fleet can lead to faster reductions in trauma. Tools and frameworks are now emerging that allow the Safe System to be quantified. The intersection design tool X-KEMM-X can now provide feedback on the injury potential of an intersection design. The Safe System Evaluation Framework provides a means for assessing alignment with the Safe System. Importantly, a treatment hierarchy has evolved that guides practitioners through treatments that best align with harm reduction. Further Safe System solutions will need to evolve and will require innovation, risk assessment and most importantly continue to look for opportunities to improve and develop practices to reduce or eliminate harm when the inevitable road user error and consequent crash occurs. Austroads 2018 | page i Towards Safe System Infrastructure: A Compendium of Current Knowledge Contents Summary ......................................................................................................................................................... i 1. Introduction ............................................................................................................................................ 1 1.1 Purpose of this report and intended audience ................................................................................. 1 1.2 Adoption of the Safe System ...........................................................................................................