Evaluation of alternative intersection treatments at rural crossroads using simulation software

Objective: Rural roads are characterised by hazardous roadsides and suboptimal geometry, yet allow for high travel speeds and unfavourable impact angles. In Victoria, 25% of persons seriously injured and 52% of fatalities occur on rural roads, with 30% occurring at intersections (Transport Accident Commision, 2016; Victorian Parliament Road Safety Committee 2002). In the USA, almost twice the number of traffic fatalities occur in rural areas than in urban areas, whilst accounting for less than half of all vehicle miles travelled and 21% of the population (NHTSA 2002). The choice of safety countermeasure is therefore paramount. Simulation software provides a cost-effective means of analysing alternative intersection treatments with a view to identifying their effectiveness in mitigating crashes. The aim of this research was to assess the safety benefits of four alternative intersection treatments using in-depth crash data with an advanced crash reconstruction process. Method: Using a single serious injury real-world crash from the MUARC Enhanced Crash Investigation Study (ECIS, Fitzharris et al., 2015) and crash reconstruction software, an exemplar rural crash was reconstructed and validated against real-world data. The crash involved a passenger vehicle (EuroNCAP 5*) approaching from a minor road and failing to yield at a ‘give-way’ sign; the posted speed limit was 80 km/h. The vehicle was struck on the right/driver side by a rigid truck (B-vehicle; 1990) travelling on the major approach (100 km/h). The driver of the case vehicle was seriously injured. Four alternative intersection treatments appropriate for the crash site were constructed in CAD software (Rhinoceros V5): roundabout; rumble strips; a reduced speed limit and the combination of lower speed limit and rumbles to determine the reduction in crash forces in the presence of the countermeasures. Results: The hypothetical scenarios demonstrate substantial reductions in impact force and different points of impact, resulting in a significantly lower injury severity for the struck driver. Speed limit reduction to 80 km/h on the main approach (from 100 km/h) in combination with rumble strips on both intersection approaches had the most favorable outcome with the crash avoided entirely, assuming speed compliance. Discussion: The findings have implications for understanding the role of speed in crashes, and hence the design of effective countermeasures. Simulation software, validated using real-world data, provides a cost effective means of evaluating alternative intersection treatments for rural intersections. Scaled up, implementing these treatments would have significant safety benefits and reduce the road trauma currently associated with rural roads

What drivers do while speeding: examining the associations between speeding and driver distraction through the Enhanced Crash Investigation Study protocol [Abstract]

This paper represents an exploratory analysis to assess the feasibility of assessing the relationship between driver speed and engagement in potentially distracting behaviours. Control data from the ECIS project are examined. These data include both objective speed measurements recorded via laser camera positioned at ECIS case-vehicle crash locations as well as retrospective self-reported driving behaviours from drivers recorded at these sites. Exploratory analysis suggests that the activities reported by drivers with recorded speeds above the limit may differ from the activities reported by those recorded on or below the limit

The MUARC-TAC enhanced crash investigation study: study update, analysis of crash types and contributing factors [Abstract]

This paper presents an update of the Monash University Accident Research Centre (MUARC) – Transport Accident Commission (TAC) Enhanced Crash Investigation Study (ECIS) as well as an exploration of the characteristics of injured drivers, crash types and factors implicated in crash occurrence. Three configurations are of particularly high frequency and severity, whilst crashes involving young and older drivers are different in nature and have different contributing factors. Fatigue, driver error, and pre-crash driver blackouts due to medical conditions were prominent contributing factors. Injury severity would be significantly lower in 32% of cases if either front or side airbags were fitted. The findings point to key risk factors that can be addressed in road safety strategies

The MUARC-TAC enhanced crash investigation study: a platform to understand the causes and consequences of serious injury crashes.

Background: In recognising the consequences of serious injury crashes, the Transport Accident Commission (TAC) commissioned Monash University Accident Research Centre (MUARC) to undertake the Enhanced Crash Investigation Study (ECIS). This paper describes the program components, seven key research questions and technical innovations used in the study. We describe the information collected and outline a ‘Safe Systems Failure Analysis’ used for each case. Project Method: Participants in ECIS include drivers aged 18 years and older seriously injured in crashes on public Victorian roads. Drivers are recruited whilst inpatients at a major trauma hospital and where possible interviews conducted. The ECIS team inspects their crashed vehicle and critically analyses the crash environment. Event Data Recorder (EDR, black-box) data is acquired from vehicles where possible and crash reconstructions are undertaken. Each case is submitted to an internal panel review with a sub-sample of cases presented to external panels throughout Victoria. This process leads to each case being submitted to a Safe Systems Failure Analysis where contributing factors and countermeasures are identified by a broad group of stakeholders. The ECIS control arm permits examination of the relationship between certain factors, such as speed and crash occurrence. Results and Discussion: In addition to describing the study, we provide an example of how the identification of crash factors, using a Safe Systems paradigm based on real-world serious injury crashes, can lead to the identification of targeted countermeasures, each with an identified policy action. Implications: This paper will demonstrate a method for creating a robust evidence base upon which government road safety policy can be built. By scaling up individual crash findings to the broader crash population, countermeasures and associated policy actions can be appropriately prioritised