Understanding the role of Speeding and Speed in Serious Crash Trauma: A Case Study of New Zealand (original) (raw)
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Traffic Crashes in New Zealand
2012
Objective To assess the validity of police-reported information on the severity of injury for non-fatal Motor Vehicle Traffic Crashes (MVTCs ). Methods Details of MVTCs reported to the police and resulting in non-fatal injury in New Zealand (NZ) from January 2000 to December 2004 were obtained from Land Transport New Zealand (L TNZ). Data about individual's injuries was matched to New Zealand Health Information Service (NZHIS) hospital discharge data. ICD-1 0 codes from the hospital data were recorded and a severity score assigned, using a Threat to Life tool, the International Classification of Diseasesbased Injury Severity Score (ICISS). Results 14,869 (51%) records were linked and used in the analysis. Of those crash victims who were recorded by police as having 'serious' injuries on the Traffic Crash Report (TCR), only 48% had an injury with a significant threat to life. Of those who were recorded as suffering a 'minor' injury on the TCR, 15% had an injury wi...
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...
Death and Injury from Motor Vehicle CrashesA Tale of Two Countries
American Journal of Preventive Medicine, 2005
To determine why road deaths dropped by 33.9% in the United Kingdom, compared to 6.5% in the United States, between 1990 and 1999. Methods: Deaths per billion vehicle kilometers traveled (D/BVKM), and case fatality rates (CFR) in the United States and the United Kingdom were tracked. Time trends in CFR can be used to track the direct effects of speed of impact. CFR is a crash-phase outcome that is independent of exposure, and varies approximately to the fourth power of the speed of crash impact. Joinpoint regression analysis was used to analyze changes in time trends of CFR. Results: In the 1990s, the decrease in deaths in the United Kingdom was attributable mostly to the 29.6% drop in the CFR. In the United States, the CFR dropped by only 6.6%. The United Kingdom introduced speed cameras and an array of speed-calming measures. By contrast, in the United States, use of speed cameras was extremely rare, and speed limits and speeds increased in 32 of the 50 states, mostly in 1995 and 1996, after which CFR actually rose (p Ͻ.0001). Intercountry differences in time trends in seat belt use, trauma care, vehicle kilometers traveled, congestion, and driving under the influence of alcohol (DUI), along with massive increase in use of higher-risk sports utility vehicles in the United States, did not account for the contrasting trends in deaths through the 1990s. But increases in DUI in the United States after 1997 may have contributed to increases in speed-related crashes. Conclusions: The reductions in CFR, probably from small drops in speed of impact account for the disproportionately greater drop in death tolls in the United Kingdom compared to the United States. The temporal fit between drops in CFR and deaths following the introduction of speed cameras in the United Kingdom and increases in speed (speed creep), CFR, and deaths in the United States following raised speed limits suggests that diverging changes in speeds of impact accounted mainly for these changes. Use of D/BVKM to correct for exposure concealed the lack of progress after 1990 in the United States, since falling time trends in D/BVKM reflect increases in congestion. If the United States had implemented United Kingdom-type speed control policies and not raised speed limits, there would have been an estimated 6500 to 10,000 (ϳ16% to 25%) fewer road deaths per year during the period following speed-limit increases (1996 to 1999), including many DUI-related deaths. Reductions of up to 50% are now achievable based on newer population-wide strategies for speed control.
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.
2007
Generalised linear models of road trauma outcomes have been found to be a powerful way of representing the trends and variations over time and to explain the effects of influential factors such as countermeasure initiatives. This report covers their application to monthly casualty crash frequencies and injury severity outcomes in Victoria during 1998 to 2003. During 2000 to 2002, the mobile speed camera program in Victoria was changed by introducing "flashless" camera operations during daytime and other modifications to make the enforcement more covert and unpredictable, increasing the targeted camera operating hours from 4200 to 6000 hours per month, and reducing the speeding offence detection threshold in three stages. In December 2002, the thresholds for penalties applying to different levels of speeding offence were generally reduced by 5 km/h. Associated with the speed enforcement initiatives was a program of speed-related advertising known as the "Wipe Off 5" campaign launched in early August 2001 without specific reference to the enforcement changes. A subsequent announcement took place in late November 2001 specifically mentioning the more covert speed camera operations as well as the increase in camera hours. A third announcement took place in the print media at the end of March 2002, emphasising that the former 9 km/h speeding tolerance no longer applied. As well as the enforcement changes, the statistical models included the reduced urban speed limit in January 2001, the penalty restructure, the speed-related advertising and the announcements, plus the impact of the fixed speed camera controversy that arose in late 2003. The study concluded that generalised linear modelling of crash outcomes as a function of potential explanatory factors needs realistic assumptions to be made about viable functional forms connecting a measure of each factor and the outcomes. The assumed functional form of the relationship between monthly speed camera hours and road trauma appears to represent this relationship well. There is doubt that the flashless speed camera initiative and the enforcement threshold reductions have been adequately represented in the monthly crash outcome models. It was concluded that the effect of these initiatives on crash outcomes is unknown at this stage. The assumed functional form of the relationship between monthly speed-related advertising levels and road trauma appears to represent this relationship well. The speed-related television advertising had a statistically significant association with a decrease in monthly casualty crash frequencies during times of increased advertising levels. In general the relationships connecting speed camera hours and levels of speed-related advertising with road trauma reductions in Victoria confirmed previous research on the effectiveness of these road safety programs as operated in the State.
Generalised linear models of road trauma outcomes have been found to be a powerful way of representing the trends and variations over time and to explain the effects of influential factors such as countermeasure initiatives. This report covers their application to monthly casualty crash frequencies and injury severity outcomes in Victoria during 1998. During 2000, the mobile speed camera program in Victoria was changed by introducing "flashless" camera operations during daytime and other modifications to make the enforcement more covert and unpredictable, increasing the targeted camera operating hours from 4200 to 6000 hours per month, and reducing the speeding offence detection threshold in three stages. In December 2002, the thresholds for penalties applying to different levels of speeding offence were generally reduced by 5 km/h. Associated with the speed enforcement initiatives was a program of speed-related advertising known as the "Wipe Off 5" campaign launched in early August 2001 without specific reference to the enforcement changes. A subsequent announcement took place in late November 2001 specifically mentioning the more covert speed camera operations as well as the increase in camera hours. A third announcement took place in the print media at the end of March 2002, emphasising that the former 9 km/h speeding tolerance no longer applied. As well as the enforcement changes, the statistical models included the reduced urban speed limit in January 2001, the penalty restructure, the speed-related advertising and the announcements, plus the impact of the fixed speed camera controversy that arose in late 2003.
Speed, Road Injury, and Public Health
Annual Review of Public Health, 2006
▪ We review milestones in the history of increases in speed limits and travel speeds (“speed creep”) and risks for road deaths and injury. Reduced speed limits, speed-camera networks, and speed calming substantially reduce these tolls in absolute numbers—a trend that is apparent in the United Kingdom, Australia, France, and other countries, but not in the United States, which has raised speed limits and does not have speed-camera networks. Newtonian relationships between the fourth power of small increases or reductions in speed and large increases or reductions in deaths state the case for speed control. Speed adaptation and the interaction between speed and other determinants of injury risks, including congestion and countermeasures, enter into these relationships. Speed-camera networks and speed calming lead to large, sustainable, and highly cost-effective drops in road deaths and injuries and should target entire populations, not merely high-risk subgroups or situations. Yet, ...
Overall impact of speed-related initiatives and factors on crash outcomes
Annual proceedings / Association for the Advancement of Automotive Medicine. Association for the Advancement of Automotive Medicine, 2007
From December 2000 until July 2002 a package of speed-related initiatives and factors took place in Victoria, Australia. The broad aim of this study was to evaluate the overall impact of the package on crash outcomes. Monthly crash counts and injury severity proportions were assessed using Poisson and logistic regression models respectively. The model measured the overall effect of the package after adjusting as far as possible for non-speed road safety initiatives and socio-economic factors. The speed-related package was associated with statistically significant estimated reductions in casualty crashes and suggested reductions in injury severity with trends towards increased reductions over time. From December 2000 until July 2002, three new speed enforcement initiatives were implemented in Victoria, Australia. These initiatives were introduced in stages and involved the following key components: More covert operations of mobile speed cameras, including flash-less operations; 50% i...