Travelling Speed and the Risk of Crash Involvement Volume 2 - Case and Reconstruction Details (original) (raw)

Travelling Speed and the Risk of Crash Involvement: Volume 1: Findings

1997

The relationship between free travelling speed and the risk of involvement in a casualty crash in a 60 km/h speed limit zone was quantified using a case control study design. The 151 case vehicles were passenger cars involved in crashes in the Adelaide metropolitan area which were investigated at the scene by the NHMRC Road Accident Research Unit at Adelaide University and reconstructed using the latest computer aided crash reconstruction techniques. The 604 control vehicles were passenger cars matched to the cases by location, direction of travel, time of day, and day of week and their speeds were measured with a laser speed gun. It was found that the risk of involvement in a casualty crash doubled with each 5 km/h increase in free travelling speed above 60 km/h. Hypothetical speed reductions applied to the case vehicles indicated large potential safety benefits from even small reductions in travelling speed, particularly on arterial roads. (a)

Travelling Speed and the Risk of Crash Involvement: The South Australian Experience

2001

The relationship between free travelling speed and the risk of involvement in a casualty crash was explored using a case control study design in two studies conducted in South Australia by the Road Accident Research Unit: one in 60 km/h speed limit zones in metropolitan Adelaide; and one in 80 km/h or greater speed limit zones in rural South Australia. Exponential increases in crash risk associated with high free travelling speeds were found in both studies and no evidence was found for an increase in risk at low free travelling speeds. Hypothetical calculations on the effect of lowering free travelling speeds in both these studies indicated that significant reductions in casualty crashes could be expected from even small reductions in free travelling speeds. The results of an alcohol case control study conducted by the Road Accident Research Unit in metropolitan Adelaide were compared to the free travelling speed studies and it was found that driving with a blood alcohol concentrat...

Driving speed and the risk of road crashes: A review

Accident Analysis & Prevention, 2006

Driving speed is an important factor in road safety. Speed not only affects the severity of a crash, but is also related to the risk of being involved in a crash. This paper discusses the most important empirical studies into speed and crash rate with an emphasis on the more recent studies. The majority of these studies looked at absolute speed, either at individual vehicle level or at road section level. Respectively, they found evidence for an exponential function and a power function between speed and crash rate. Both types of studies found evidence that crash rate increases faster with an increase in speed on minor roads than on major roads. At a more detailed level, lane width, junction density, and traffic flow were found to interact with the speed-crash rate relation. Other studies looked at speed dispersion and found evidence that this is also an important factor in determining crash rate. Larger differences in speed between vehicles are related to a higher crash rate. Without exception, a vehicle that moved (much) faster than other traffic around it, had a higher crash rate. With regard to the rate of a (much) slower moving vehicle, the evidence is inconclusive.

Travelling Speed and the Risk of Crash Involvement on Rural Roads

2001

The relationship between free travelling speed and the risk of involvement in a casualty crash in 80 km/h or greater speed limit zones in rural South Australia was quantified using a case control study design. The crashes involving the 83 case passenger vehicles were investigated at the scene by the Road Accident Research Unit and reconstructed using the latest computer aided crash reconstruction techniques. The 830 control passenger vehicles were matched to the cases by location, direction of travel, time of day, and day of week, and their speeds were measured with a laser speed gun. It was found that the risk of involvement in a casualty crash increased more than exponentially with increasing free travelling speed above the mean traffic speed and that travelling speeds below the mean traffic speed were associated with a lower risk of being involved in a casualty crash. The effect of hypothetical speed reductions on all of the 167 crashes investigated indicated large potential safe...

Speed related variables for crash injury risk analysis: what has been used?

International Journal of Crashworthiness, 2021

Speed is a major risk factor in overall road safety performance. The objective of this study was to identify the most frequent explanatory variables and measures used to investigate the speed factor contribution to crash injury risk (CIR). For this purpose, a literature oriented approach was used. The analysis review, underpinned by data collected from 64 journal publications reported over the past 21 years shows that speed limit was the most frequently used variable selected by the authors to investigate speed contribution CIR. Following, speed delta-V was the second most used variable, despite the barriers to access in-depth crash quality data. Even so, the speed limit was used 3.5 times more than delta-V, possibly due to the facilitate accessibility to the roads standardize posted speed limits. However, it is unknown how much vehicles travel speed could deviate from the posted speed limit at the moment of the crash.

Response by Monash University Accident Research Centre

2000

This document is the response by Monash University Accident Research Centre (MUARC) to an investigation of some specific MUARC research. The investigation has been published by the South Australian Department of Transport . It relates principally to MUARC's research on traffic enforcement and road safety advertising in Victoria. From re-analysis of data used in MUARC report no. 74, White et al have concluded that the estimates of crash and financial savings attributable to the TAC-funded countermeasures are not supportable. They have also concluded that the re-analysis has failed to support the claims of MUARC report no. 52 concerning the crash reductions that can be achieved through high levels of TAC-funded road safety television advertising.

Developments in the Risk of Crash Involvement

Crash test based consumer information systems, such as EuroNCAP or US NCAP, have indicated a substantial reduction in the risk of serious injury to car occupants since the mid-1990s. In parallel with these improving experimental results, there has been a steady reduction in the total numbers of car occupants seriously or fatally injured and it has been generally assumed that improved crash protection accounts for much of the reductions observed societally. Nevertheless, there has been very little analysis of the relationship between experimental results and any real reductions in casualties because of the influence of confounding effects of other parameters including the exposure to risk of different categories of vehicle and the underlying trends in mobility. This paper uses UK national accident data and recently available exposure data to evaluate the developments of risk of fatal or serious injury in parallel with the risks of crash involvement.

Proposed vehicle impact speed - severe injury probability relationships for selected crash types

2015

Speed is recognised as a key contributor to crash likelihood and severity, and to road safety performance in general. Its fundamental role has been recognised by making Safe Speeds one of the four pillars of the Safe System. In this context, impact speeds above which humans are likely to sustain fatal injuries have been accepted as a reference in many Safe System infrastructure policy and planning discussions. To date, there have been no proposed relationships for impact speeds above which humans are likely to sustain fatal or serious (severe) injury, a more relevant Safe System measure. A research project on Safe System intersection design required a critical review of published literature on the relationship between impact speed and probability of injury. This has led to a number of questions being raised about the origins, accuracy and appropriateness of the currently accepted impact speed–fatality probability relationships (Wramborg 2005) in many policy documents. The literature...