Rural intersections present unique road safety issue: they are numerous and typically have low cr... more Rural intersections present unique road safety issue: they are numerous and typically have low crash counts. Hence, crash history can be a poor predictor of future safety performance. Given that 10% of all Victorian severe crash injuries occur at rural intersections, their effective prioritisation for improvement is a priority. This paper explores prioritisation of rural intersections based on severe injury estimates using three alternative approaches. The findings show that predictive models based on traffic flow, road hierarchy, intersection type, and maximum speed limit optimise both prioritisation logic and ease of applicability. These findings may be useful in development of future safety infrastructure investment programs.
This report incorporates recent research, best practice examples, and jurisdictional inputs to pr... more This report incorporates recent research, best practice examples, and jurisdictional inputs to propose a set of model national speed limit guidelines for setting speed limits at high-risk locations. The model guidelines represent a harm reduction approach to speed limits, an intermediate step towards the Safe System. The model guidelines are intended to apply to different road categories and functions typical to Australia, while incorporating criteria for reduced speed limits based on severe crash risk, such as: road lengths that are narrow, have a substantial level of roadside hazards, have many intersections or property entrances, are curvilinear or undulating, or have higher than average severe casualty crash rates higher-risk intersections, especially on high-volume outer-urban arterials, where engineering treatments are not feasible. The model guidelines aim to provide consistent speed limits on roads and intersections which have a higher severe crash risk, while minimising multiple speed zones over short distances. About Austroads Austroads' purpose is to: • promote improved Australian and New Zealand transport outcomes • provide expert technical input to national policy development on road and road transport issues • promote improved practice and capability by road agencies. • promote consistency in road and road agency operations.
The Journal of the Australasian College of Road Safety, 2012
The findings presented in this paper are based on Austroads-funded investigations of the in-servi... more The findings presented in this paper are based on Austroads-funded investigations of the in-service effectiveness of safety barriers on high-speed roads (that is, roads with 100 and 110 km/h speed limits). Based on past evaluations, the most promising was continuous application of flexible barriers on freeways addressing up to 86% of run-off-road and cross-median casualty crashes. Analysis of Victorian barrier crash data from high-speed roads suggested that the severity index for run-off-road casualty crashes (FSI ratio) was 0.58 for semi-rigid barrier crashes compared with 0.75 for tree crashes. Severity of run-off-road casualty crashes into semi-rigid barriers was comparable to those not involving a roadside hazard (FSI ratio of 0.55). In contrast, flexible barriers had the lowest FSI ratio of 0.38. Continuous flexible barriers appeared to be the most effective safety barrier solution among those reviewed. Investigation of the effect of semi-rigid barrier offset from the edge line...
... Jurewicz, Chris 1. Abstract: This paper explores the effectiveness of key Local Area Traffic ... more ... Jurewicz, Chris 1. Abstract: This paper explores the effectiveness of key Local Area Traffic Management (LATM) treatment types in reducing traffic speeds and, hence, in reducing the risk of casualty crashes on local roads. ... [cited 24 Oct 10]. Personal Author: Jurewicz, Chris. ...
The Safe System vision (known as Vision Zero, or Sustainable Safety in Europe) aspires to minimis... more The Safe System vision (known as Vision Zero, or Sustainable Safety in Europe) aspires to minimise death and serious injury as an outcome of road travel for all road users. The road engineering contribution to this vision focusses on impact elimination, or where this is not possible, on limiting kinetic energy passed to a road user in case of an impact. Impact kinetic energy is typically limited through vehicle speed management (e.g. speed limits, enforcement or geometric road design), as vehicle mass is difficult to effectively control by public road agencies. This paper reviews available international research on relationships between impact velocity change (delta-v), impact speeds and the probability of fatal and serious injury (MAIS3+) across a range of common crash scenarios. Based on the best identified relationships, and with assumption of equal mass and vehicle speeds, right-angle and head-on impact speeds of approximately 30 km/h are likely to produce MASI3+ injury probability of approximately 10%, considered a critical threshold in Safe System discussions. For pedestrians, the threshold is likely to be even lower, approximately 20 km/h. In rear-end crashes, the critical impact speed was found to be approximately 55 km/h. Some practical applications of these findings are discussed. The paper discusses the assumptions and limitations behind the available evidence, and outlines the proposed research to strengthen it.
Journal of the Australasian College of Road SafetyFebruary 2010 17 Recent Progress in Implementi... more Journal of the Australasian College of Road SafetyFebruary 2010 17 Recent Progress in Implementing the Safe System Approach By Blair Turner, Peter Cairney, Chris Jurewicz & David McTiernan ARRB Dmitry Medvedev and a series of panel sessions on partnerships, policy, health ...
This project forms part of a major Austroads strategic research program to improve the understand... more This project forms part of a major Austroads strategic research program to improve the understanding of the relationships between crash risk, road infrastructure and traffic operations. A crash rating database was created for seven Australian jurisdictions. It used GIS systems to combine crash information with road feature and traffic flow data, and thus provided a platform for detailed analysis of crash risks in different road environments. Mean crash rates and crash cost rates were developed for different road link and intersection types in different jurisdictions. General conclusions regarding the safety of travel on different parts of the road network were drawn based on these figures. The project also presented practical examples of database application through development of safety performance functions and crash rate functions based on different road feature attributes, such as: lane width, terrain, horizontal alignment, road type or traffic control type. The Austroads Crash ...
This paper presents the findings of an Austroads project carried out by ARRB investigating the im... more This paper presents the findings of an Austroads project carried out by ARRB investigating the impacts of road safety-based lower speed limits on network operations. There is a strong link between vehicle speeds and road safety, as recognised by the Safe System approach. Under speed management strategies implemented by Australasian jurisdictions, speed limits are sometimes lowered with the aim of producing lower vehicle speeds, and thus, quantifiable reductions in crashes. The project provided an overview of the current state of research on the impacts of lower speed limits on the network operation indicators such as: travel speeds, journey times, traffic flow, air pollutant emissions, fuel consumption and the overall economic costs. These findings were extended by estimating the impacts of lower speed limits on urban arterial roads with interrupted traffic flow (signals, roundabouts). Microsimulation modelling of several arterial routes operating under peak-hour traffic conditions ...
Rural intersections present unique road safety issue: they are numerous and typically have low cr... more Rural intersections present unique road safety issue: they are numerous and typically have low crash counts. Hence, crash history can be a poor predictor of future safety performance. Given that 10% of all Victorian severe crash injuries occur at rural intersections, their effective prioritisation for improvement is a priority. This paper explores prioritisation of rural intersections based on severe injury estimates using three alternative approaches. The findings show that predictive models based on traffic flow, road hierarchy, intersection type, and maximum speed limit optimise both prioritisation logic and ease of applicability. These findings may be useful in development of future safety infrastructure investment programs.
This report incorporates recent research, best practice examples, and jurisdictional inputs to pr... more This report incorporates recent research, best practice examples, and jurisdictional inputs to propose a set of model national speed limit guidelines for setting speed limits at high-risk locations. The model guidelines represent a harm reduction approach to speed limits, an intermediate step towards the Safe System. The model guidelines are intended to apply to different road categories and functions typical to Australia, while incorporating criteria for reduced speed limits based on severe crash risk, such as: road lengths that are narrow, have a substantial level of roadside hazards, have many intersections or property entrances, are curvilinear or undulating, or have higher than average severe casualty crash rates higher-risk intersections, especially on high-volume outer-urban arterials, where engineering treatments are not feasible. The model guidelines aim to provide consistent speed limits on roads and intersections which have a higher severe crash risk, while minimising multiple speed zones over short distances. About Austroads Austroads' purpose is to: • promote improved Australian and New Zealand transport outcomes • provide expert technical input to national policy development on road and road transport issues • promote improved practice and capability by road agencies. • promote consistency in road and road agency operations.
The Journal of the Australasian College of Road Safety, 2012
The findings presented in this paper are based on Austroads-funded investigations of the in-servi... more The findings presented in this paper are based on Austroads-funded investigations of the in-service effectiveness of safety barriers on high-speed roads (that is, roads with 100 and 110 km/h speed limits). Based on past evaluations, the most promising was continuous application of flexible barriers on freeways addressing up to 86% of run-off-road and cross-median casualty crashes. Analysis of Victorian barrier crash data from high-speed roads suggested that the severity index for run-off-road casualty crashes (FSI ratio) was 0.58 for semi-rigid barrier crashes compared with 0.75 for tree crashes. Severity of run-off-road casualty crashes into semi-rigid barriers was comparable to those not involving a roadside hazard (FSI ratio of 0.55). In contrast, flexible barriers had the lowest FSI ratio of 0.38. Continuous flexible barriers appeared to be the most effective safety barrier solution among those reviewed. Investigation of the effect of semi-rigid barrier offset from the edge line...
... Jurewicz, Chris 1. Abstract: This paper explores the effectiveness of key Local Area Traffic ... more ... Jurewicz, Chris 1. Abstract: This paper explores the effectiveness of key Local Area Traffic Management (LATM) treatment types in reducing traffic speeds and, hence, in reducing the risk of casualty crashes on local roads. ... [cited 24 Oct 10]. Personal Author: Jurewicz, Chris. ...
The Safe System vision (known as Vision Zero, or Sustainable Safety in Europe) aspires to minimis... more The Safe System vision (known as Vision Zero, or Sustainable Safety in Europe) aspires to minimise death and serious injury as an outcome of road travel for all road users. The road engineering contribution to this vision focusses on impact elimination, or where this is not possible, on limiting kinetic energy passed to a road user in case of an impact. Impact kinetic energy is typically limited through vehicle speed management (e.g. speed limits, enforcement or geometric road design), as vehicle mass is difficult to effectively control by public road agencies. This paper reviews available international research on relationships between impact velocity change (delta-v), impact speeds and the probability of fatal and serious injury (MAIS3+) across a range of common crash scenarios. Based on the best identified relationships, and with assumption of equal mass and vehicle speeds, right-angle and head-on impact speeds of approximately 30 km/h are likely to produce MASI3+ injury probability of approximately 10%, considered a critical threshold in Safe System discussions. For pedestrians, the threshold is likely to be even lower, approximately 20 km/h. In rear-end crashes, the critical impact speed was found to be approximately 55 km/h. Some practical applications of these findings are discussed. The paper discusses the assumptions and limitations behind the available evidence, and outlines the proposed research to strengthen it.
Journal of the Australasian College of Road SafetyFebruary 2010 17 Recent Progress in Implementi... more Journal of the Australasian College of Road SafetyFebruary 2010 17 Recent Progress in Implementing the Safe System Approach By Blair Turner, Peter Cairney, Chris Jurewicz & David McTiernan ARRB Dmitry Medvedev and a series of panel sessions on partnerships, policy, health ...
This project forms part of a major Austroads strategic research program to improve the understand... more This project forms part of a major Austroads strategic research program to improve the understanding of the relationships between crash risk, road infrastructure and traffic operations. A crash rating database was created for seven Australian jurisdictions. It used GIS systems to combine crash information with road feature and traffic flow data, and thus provided a platform for detailed analysis of crash risks in different road environments. Mean crash rates and crash cost rates were developed for different road link and intersection types in different jurisdictions. General conclusions regarding the safety of travel on different parts of the road network were drawn based on these figures. The project also presented practical examples of database application through development of safety performance functions and crash rate functions based on different road feature attributes, such as: lane width, terrain, horizontal alignment, road type or traffic control type. The Austroads Crash ...
This paper presents the findings of an Austroads project carried out by ARRB investigating the im... more This paper presents the findings of an Austroads project carried out by ARRB investigating the impacts of road safety-based lower speed limits on network operations. There is a strong link between vehicle speeds and road safety, as recognised by the Safe System approach. Under speed management strategies implemented by Australasian jurisdictions, speed limits are sometimes lowered with the aim of producing lower vehicle speeds, and thus, quantifiable reductions in crashes. The project provided an overview of the current state of research on the impacts of lower speed limits on the network operation indicators such as: travel speeds, journey times, traffic flow, air pollutant emissions, fuel consumption and the overall economic costs. These findings were extended by estimating the impacts of lower speed limits on urban arterial roads with interrupted traffic flow (signals, roundabouts). Microsimulation modelling of several arterial routes operating under peak-hour traffic conditions ...
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