Effect of eco-driving on commercial motor vehicle driver collision risk.

INTRODUCTION: This study investigates the effect among commercial motor vehicle (CMV) drivers of the adoption of fuel-efficient driving techniques (commonly known as eco-driving) on the odds of being involved in safety-related events. METHOD: For 2,637 long-haul class 8 drivers employed by four carriers in Canada, information on driving style, total distance driven, and safety-related events like collisions, hard-braking, hard-turning, and stability control events were collected for each trip. Three carriers provided driving style-related data from the ISAAC instrument, which provides a score on a 0 to 100 scale that measures the degree to which a driver is using an appropriate amount of engine power according to driving conditions. The fourth carrier provided data on driving style characteristics, including fuel consumption, use of cruise control, and use of top gear. Depending on the carrier, information on speeding, driver age, and years of experience driving a commercial vehicle was also collected. Logit statistical models were developed to estimate the change in odds of a driver experiencing a safety-related event dependent on the measures of driving style. RESULTS: A one-unit increase in the ISAAC score was associated with a 7%, 8%, 8%, and 4% reduction in the odds of having a hard-braking event, hard left-turn event, hard right-turn event, and collision, respectively. For the carrier not employing the ISAAC system, an increase of 10% in the time spent driving in top gear with steady speed near 100 km per hour (km/h) was associated with a substantial 34% decrease in stability control events. In addition, a year increase in the driver's age, as well as a 1% increase in the amount of time spent driving using cruise control, reduced the number of hard-braking events by 9% and 3%, respectively. Conclusion/Practical Applications: The adoption of fuel-efficient driving techniques enhances the safety of CMV drivers.

Assessing the effect of automated speed enforcement and comprehensive measures on road safety in Rwanda.

OBJECTIVES: Daily, approximately 3,400 traffic-related deaths occur globally, with over 90% concentrated in low and middle-income countries (LMICs). Notably, Rwanda has one of the highest road traffic death rates in the world (29.7 per 100,000 people) and is the first low-income country to implement a national Automated Speed Enforcement (ASE) policy. The primary goal of this study is to evaluate the effectiveness of ASE cameras in reducing the primary outcome of road traffic deaths and secondary outcomes of serious injury crashes and fatal crashes. METHODS: The study used data on road traffic deaths, and serious injury and fatal crashes collected by the Rwanda National Police between 2010 and 2022. Interrupted time series (ITS) models were fit to quantify the association between ASE and change in road traffic crash outcomes, adjusted for COVID-19-related variables (such as the start of the pandemic, the closure of schools and bars), along with exposure variables (such as GDP and population), and other concurrent road safety measures (such as road safety campaigns). RESULTS: The ITS models show that the implementation of ASE cameras significantly reduced road traffic deaths, serious injury crashes, and fatal crashes at the provincial level. For instance, the implementation of ASE cameras in the whole of Rwanda in April 2021 was significantly associated with a 0.14 (95% CI [0.072, 0.212]) reduction in monthly death incidence, equating to a 38.16% monthly decrease compared to the period before their installation (January 2010-March 2021). CONCLUSION: This study emphasizes the significant association of ASE in Rwanda with improved road traffic crash outcomes, a result that may inform road safety policy in other LMICs. Rwanda has become the first low-income country to implement nationwide scaling of ASE in Africa, paving the way for the generation of valuable evidence on speed-related interventions. In addition to new knowledge generation, African road safety research efforts like this one are opportunities to grow academic and law enforcement cooperations while improving data systems and sources for future research benefits.

Prevalence and trends of distracted driving in Canada.

INTRODUCTION: This study evaluates prevalence and trends in distracted driving in Canada based on multiple indicators collected from the Road Safety Monitor (RSM) and Canada's National Fatality Database maintained by the Traffic Injury Research Foundation (TIRF). METHOD: Data from the RSM on self-reported distracted driving behaviors were analyzed using multivariate techniques including logistic regression analysis in various years spanning from 2004 to 2019. Data from TIRF's National Fatality Database from 2000 to 2016 were also analyzed using piecewise regression analysis to evaluate trends and prevalence of driver distraction. RESULTS: Significantly more Canadians reported talking on their phone hands-free or handheld phone while driving in 2019 compared to 2010. There was a 102% increase in the percentage that reported texting while driving in 2019 (9.7%) compared to 2010 (4.8%). For every 10-year increase in age, drivers were 44% less likely to text, 38% less likely to use a handheld phone, and 28% less likely to use a hands-free phone. Males were 62% more likely to use a handheld phone and 50% more likely to use a hands-free phone than females. Findings related to drivers' perceived danger of distracted driving and attitudes are also presented. Although the number of distraction-related fatalities has not increased substantially from 2000 to 2016, the percentage of all fatalities where distraction was a contributing factor has increased. Unlike drinking drivers, distracted drivers more often kill other road users in crashes than kill themselves. CONCLUSIONS: In conclusion, while most Canadians appear to understand that one of the high-risk forms of distracted driving (i.e., texting while driving) is indeed dangerous, there is a minority who are unaware of, or resistant to, this fact. Practical Applications: Enforcement activities and education initiatives to combat distracted driving ought to be tailored to the target audience based on the patterns uncovered.

Automated vehicles and older drivers in Canada.

INTRODUCTION: As seniors represent a growing proportion of the driving population, research about how automated vehicles can help improve older driver safety and mobility is highly relevant. This paper examines the knowledge, attitudes and perceptions of older drivers towards limited self-driving vehicles (LSDVs), and how these variables can influence the likelihood that they will rely on this technology. METHOD: The study includes data from a previous national survey (N = 2662) about automated vehicle technology, with new analyses to test hypothetical models using structural equation modeling. Results of the first model were confirmed and built upon with a second more complex model that incorporated the construct "behavioral adaptation." Focus groups with older drivers were also conducted (N = 38) to help reveal nuances in older drivers' knowledge, attitudes, perceptions, and behaviors regarding this technology. RESULTS: Survey results demonstrated that feelings of safety and knowledge about LSDVs are positively related to perceived ease of use and adoption of the technology. The positive association between safety and perceived ease of use was further highlighted when comparing responses of older drivers to those of younger age groups, as older drivers were significantly less likely to agree that LSDVs were easy to use and were significantly less agreeable about feeling safe using them. Focus groups results confirmed that safety and knowledge of LSDVs are essential to the likelihood of adopting this technology, and revealed a high receptivity among older drivers to educational strategies and tools to increase their knowledge of LSDVs. Implications for educational strategies and safety benefits for older drivers are discussed. Practical applications: Results provide insight into strategies to encourage the early adoption of automated vehicles by older drivers and facilitate a safer transition towards automated vehicles that is lead by a cohort of safety-conscious drivers.

Canadian wildlife-vehicle collisions: An examination of knowledge and behavior for collision prevention.

OBJECTIVES: This study examines drivers' responses to wildlife on Canadian roads. The objective of this paper is to demonstrate that knowledge of what to do when encountering wildlife on the road does not always translate into the appropriate behavior to avoid a collision. METHODS: Data from the Traffic Injury Research Foundation's (TIRF) 2016 Road Safety Monitor (RSM) and data from TIRF's National Fatality Database from 2000 to 2014 were analyzed to test hypotheses based on the theory of planned behavior. Logistic regression and piecewise linear regression were used. RESULTS: Analyses of the data showed that the prevalence of fatal WVCs has remained relatively consistent, and that the majority of persons killed in WVCs died in crashes that involved large mammals. The majority of fatalities occurred in the summer (182 or 38.4%) and fall (163 or 34.4%). The RSM data revealed that 60.9% [50.5, 70.4] of respondents who previously hit an animal indicated that drivers should slow down and steer straight when confronted with wildlife, while 47.3% [37.1, 57.6] of respondents indicated this was the action they took when they hit wildlife. Comparatively, 59.5% [56.6, 62.4] of respondent who have not hit an animal indicated this was an appropriate response. Additionally, 33.2% [24, 44] of respondents who previously hit an animal indicated that drivers should swerve to avoid a collision with wildlife, while 37.5% [28.2, 47.8] of respondents indicated this was the action they took when they hit wildlife. CONCLUSIONS: Many drivers are unaware of what the safest method of WVC prevention is. Further, while a subgroup of drivers may have the knowledge and intention to slow down and steer straight even if the animal is directly in the path, i.e., the safest possible behavior, they are not necessarily adopting this behavior. Practical applications: Recommendations are formulated to address this discrepancy, as well as practical applications.

Impact evaluation of camera enforcement for traffic violations in Cali, Colombia, 2008-2014.

INTRODUCTION: Cameras for detecting traffic violations have been used as a measure to improve road safety in different countries around the world. In Cali, Colombia, fixed cameras were installed in March 2012 on a number of roads and intersections. All camera devices are capable of detecting simultaneously the following traffic violations: driving over the speed limit, running a red light or stop sign, violation of the traffic ban schedule, and blocking the pedestrian crosswalk. OBJECTIVE: To evaluate the impact of camera enforcement of traffic violations in Cali, Colombia. METHODS: A quasi-experimental difference-in-differences study with before and after measurements and a comparison group was conducted. We observed 38 intervention areas and 50 comparison areas (250 m radius), during 42 months before and 34 months after the installation of cameras. Effects were estimated with mixed negative binomial regression models. RESULTS: In intervention areas, after 12 months, there was a reduction of 19.2% of all crashes and a 24.7% reduction of injury and fatal crashes. In comparison areas, this reduction was 15.0% for all crashes and 20.1% for injury and fatal crashes. After adjusted comparisons, intervention sites outperformed comparison sites with an additional yearly reduction of 5.3% (p = 0.045) for all crashes. CONCLUSIONS: The use of cameras for detecting traffic violations seems to have a positive effect on the reduction of crashes in intervention areas. A beneficial spillover effect was found as well in comparison areas; but more evaluations are needed.

Less is more: the influence of traffic count on drinking and driving behaviour.

Drinking and driving road checks are often organized with either a clear prevention or repression objective in mind. The objective of a prevention strategy is to make as many people as possible believe that police officers are enforcing drinking and driving laws and that drinking drivers will most likely be caught. As such, targeting high traffic count road sites with high-visibility road checks is a priority because it serves to increase awareness of the enforcement activity. An alternative to this prevention approach is the "repression" approach that involves targeting times and places where the highest number of drinking drivers are to be expected. Rather than attempting to affect the subjective chance of getting caught, this approach seeks to increase the objective likelihood of getting caught; the aim is to apprehend as many drinking drivers as possible. Regardless of the chosen strategy, there is a need to understand how traffic count influences drinking and driving behaviour as traffic count may play a role in a police officer's choice of sites for a road check. The objective of this paper is to shed some light on this relationship between drinking and driving behaviour and traffic count. In this paper, data from a roadside survey, carried out in British Columbia in 2003, are used. A two-level logistic regression analysis was carried out with data from 2627 drivers coming from 48 different road sites to replicate a model that was previously obtained with comparable data from a Belgian roadside survey, also carried out in 2003. The present study successfully replicated the findings of the Belgian model, substantiating that the probability for drivers to be drinking and driving significantly decreases with an increasing level of traffic count. This supports the suggestion that drinking drivers avoid high traffic count road sites. The relevance of these findings with respect to organizing preventive or repressive road checks and possible confounding variables are discussed at the end of this paper.

Aggressive driving: a survey of attitudes, opinions and behaviors.

INTRODUCTION: Aggressive driving encompasses a continuum of behaviors that range from extreme acts, such as shootings, to less severe manifestations, such as arguments and gestures. It is clear from the available data that aggressive driving is not uncommon and very risky. However, little is known about the opinions and practices of drivers. The purpose of this study was to help bridge these gaps. METHODS: The data were gathered by means of a public opinion poll among a representative sample of 1,201 Canadian drivers. Univariate frequency distributions and 95% confidence intervals were calculated and logistic regression and generalized linear latent models were used to summarize the data. RESULTS: It was found that the issue of aggressive driving is a significant one as a considerable percentage of drivers admits to it. The results coming from the logistic regression and the generalized linear latent model suggest that male and younger drivers are more likely to behave aggressively in traffic and that behaving more aggressively is associated with a history of traffic tickets. DISCUSSION: When gauging people's attitudes, opinions, and behaviors, it becomes clear that aggressive driving is a considerable problem. There also seems to be a need for a better understanding of which specific behaviors respondents associate with the generic term "aggressive driving." IMPACT ON INDUSTRY: Results from this study further emphasize the need of increasing the aggressive driving knowledge base.

Fatigued and drowsy driving: a survey of attitudes, opinions and behaviors.

INTRODUCTION: There is evidence suggesting that the problem of fatigued or drowsy driving is an important contributor to road crashes. However, not much is known about public perceptions of the issue. The purpose of this study was to obtain information on attitudes, opinions, and professed practices related to fatigued or drowsy driving. METHODS: The data were gathered by means of a public opinion poll among a representative sample of 750 Ontario drivers. RESULTS: A majority of drivers (58.6%) admitted that they occasionally drive while fatigued or drowsy. Of greater importance, 14.5% of respondents admitted that they had fallen asleep or "nodded off" while driving during the past year. Nearly 2% were involved in a fatigue or drowsy driving related crash in the past year. Respondents were also asked about measures they take to overcome fatigue or drowsiness. Results indicate that relatively ineffective measures such as opening the window or playing music are the most popular; the most effective preventive measure--taking a rest--is the least popular. DISCUSSION: The prevalence of the behavior, coupled with the ineffective prevention measures favored by the public suggest there is a need for increasing their level of awareness and knowledge about the problem. IMPACT ON INDUSTRY: Results from this study further emphasize the importance of increasing the fatigued and drowsy driving knowledge base and the need to educate the public about it.

An evaluation of Nova Scotia's alcohol ignition interlock program.

Alcohol ignition interlock programs for offenders aim to reduce recidivism among convicted drink drivers. This study presents an evaluation of Nova Scotia's interlock program implemented in 2008 in order to assess its effectiveness to reduce impaired driving and to help identify areas for improvement. Data used include conviction and crash records of individual participants; provincial monthly counts of alcohol-related charges, convictions and fatal and serious crashes; and interlock logged events. Methods used include descriptive statistics, survival analysis, time series and logistic regression analysis. With respect to specific deterrence (i.e., preventing recidivism) there was a 90% reduction in recidivism among voluntary participants since participation in the interlock program and a 79% reduction after these participants exited from the program. With respect to general deterrence (i.e., referring to a preventative effect on the entire population of drivers in Nova Scotia) there were temporary decreases in the numbers of alcohol-related charges (13.32%) and convictions (9.93%) and a small significant decrease in the number of fatal and serious injury alcohol-related crashes, following the implementation of the program. The evidence suggests the interlock program was better at preventing harm due to alcohol-impaired driving than the alternative of not using the interlock program. Recommendations were formulated supporting the continuation of the interlock program in Nova Scotia.

Canadian drivers' attitudes regarding preventative responses to driving while impaired by alcohol.

BACKGROUND: In many jurisdictions, a risk assessment following a first driving while impaired (DWI) offence is used to guide administrative decision making regarding driver relicensing. Decision error in this process has important consequences for public security on one hand, and the social and economic well being of drivers on the other. Decision theory posits that consideration of the costs and benefits of decision error is needed, and in the public health context, this should include community attitudes. The objective of the present study was to clarify whether Canadians prefer decision error that: i) better protects the public (i.e., false positives); or ii) better protects the offender (i.e., false negatives). METHODS: A random sample of male and female adult drivers (N=1213) from the five most populated regions of Canada was surveyed on drivers' preference for a protection of the public approach versus a protection of DWI drivers approach in resolving assessment decision error, and the relative value (i.e., value ratio) they imparted to both approaches. The role of region, sex and age on drivers' value ratio were also appraised. RESULTS: Seventy percent of Canadian drivers preferred a protection of the public from DWI approach, with the overall relative ratio given to this preference, compared to the alternative protection of the driver approach, being 3:1. Females expressed a significantly higher value ratio (M=3.4, SD=3.5) than males (M=3.0, SD=3.4), p<0.05. Regression analysis showed that both days of alcohol use in the past 30days (CI for B: -0.07, -0.02) and frequency of driving over legal BAC limits in the past year (CI for B=-0.19, -0.01) were significantly but modestly related to lower value ratios, R2(adj.)=0.014, p<0.001. Regional differences were also detected. CONCLUSIONS: Canadian drivers strongly favour a protection of the public approach to dealing with uncertainty in assessment, even at the risk of false positives. Accounting for community attitudes concerning DWI prevention and the individual differences that influence them could contribute to more informed, coherent and effective regional policies and prevention program development.

Prevalence and trends of drugged driving in Canada.

OBJECTIVES: This study evaluates prevalence and trends in drugged driving in Canada based on multiple indicators collected from the Road Safety Monitor (RSM) and Canada's National Fatality Database maintained by the Traffic Injury Research Foundation (TIRF). The objective of this paper is to identify the state of drug-positive driving in Canada, as well as to make comparisons with data from previous years to determine whether changes have occurred. METHODS: Available data from the RSM on self-reported drugged driving behaviours were collected and analyzed using multivariate techniques in various years spanning from 2002 to 2015. Data from TIRF's National Fatality Database from 2000 to 2012 were also analyzed to evaluate trends and prevalence of drugs in fatally injured drivers across Canada. Additionally, differences among drugged drivers with respect to gender and age were studied. RESULTS: Analyses of the RSM data and of the National Fatality Database showed that, as a whole, the prevalence of drugged driving has remained relatively stable over the past decade, with some changes noticed in specific years for some drug types. Specifically from the RSM, there was a 62.5% increase from the 1.6% of drivers reporting driving within two hours of using marijuana in 2013 to 2.6% in 2015. The analyses of the fatality data revealed a 16.9% increase in the percentage of fatally injured drivers testing positive for drugs between 2000 and 2012 (from 33.56% to 39.24%). Cocaine-positive fatally injured drivers increased from 3.6% in 2000 to 6.2% in 2012. Similarly, marijuana-positive fatally injured drivers increased from 12.8% in 2000 to 19.7% in 2012. Results showed varying characteristics with respect to gender and age among self-reported and fatally injured drugged drivers. CONCLUSIONS: Drugged driving behaviours remain prevalent among Canadian drivers and drugs continue to be found in over one-third of tested fatally injured drivers. Although self-reported behaviours have neither decreased nor increased overall in the past decade according to RSM data, with the exception of driving within two hours of using marijuana, data from fatally injured drivers reveal that small, but significant increases in some behaviours have occurred.

Perception of road accident causes.

A theoretical two-dimensional model on prevalence and risk was developed. The objective of this study was to validate this model empirically to answer three questions: How do European drivers perceive the importance of several causes of road accidents? Are there important differences in perceptions between member states? Do these perceptions reflect the real significance of road accident causes? Data were collected from 23 countries, based on representative national samples of at least 1000 respondents each (n=24,372). Face-to-face interviews with fully licensed, active car drivers were conducted using a questionnaire containing closed answer questions. Respondents were asked to rate 15 causes of road accidents, each using a six-point ordinal scale. The answers were analyzed by calculating Kendall's tau for each pair of items to form lower triangle similarity matrices per country and for Europe as a whole. These matrices were then used as the input files for an individual difference scaling to draw a perceptual map of the 15 items involved. The hypothesized model on risk and prevalence fits the data well and enabled us to answer the three questions of concern. The subject space of the model showed that there are no relevant differences between the 23 countries. The group space of the model comprises four quadrants, each containing several items (high perceived risk/low perceived prevalence items; high perceived risk/high perceived prevalence items; low perceived risk/high perceived prevalence items and low perceived risk/low perceived prevalence items). Finally, perceptions of the items driving under the influence of alcohol, drugs and medicines and driving using a handheld or hands-free mobile phone are discussed with regard to their real significance in causing road accidents. To conclude, individual difference scaling offers some promising possibilities to study drivers' perception of road accident causes.

The dilemma of re-licensing DWI offenders: The offenders' point of view.

In many jurisdictions, drivers convicted for the first-time of driving while impaired by alcohol undertake a risk assessment that will determine the severity of sanctions and the remedial measures they must follow as requisites for re-licensing. There is uncertainty inherent in the assessment of risk for recidivism, however, many offenders feel unfairly assessed and discommoded by the decision-making process and its consequences. The objective of this qualitative study was to gain insight into the perspectives of offenders regarding re-licensing decision making and sanctioning. Specifically, in focus groups first-time offenders and recidivists were probed as to whether they favoured erring on the side of road safety in decision making, with its consequent greater risk of false positive assessments, or erring on the side of maintaining driving privileges, with its consequent greater risk of false negative assessments. In general, participants preferred a higher probability of false negative vs. false positive assessments. Most cited the consequences of sanctions and remedial measures as too severe to impose them on potentially low-risk drivers, as the assessment and monitoring protocols' limitations could lead to non-equitable treatment. At the same time, recidivists evoked a greater preference for a higher probability of false positive assessments compared to first-time offenders, as they believed that recidivism was more likely to follow a first conviction than did first-time offenders. This information can be useful for a more comprehensive and societally coherent exercise of DWI prevention policies.

An evaluation of Ontario's Group Education Session (GES) for license renewal of seniors aged 80 and above.

INTRODUCTION: In 1996, the Ministry of Transportation in Ontario (MTO) implemented the Group Education Session (GES), which is a mandatory license renewal program for drivers aged 80 and older. This study describes an evaluation of the GES to assess its impact on road safety in Ontario, as well as its effect on the safety of individual drivers who participated in the program. METHODS: Time series analysis of senior driver records both before and after implementation of the GES, and logistic regression and survival analysis examining senior driver records prior to, and following, their participation in the GES. RESULTS: Using time series analysis there is some evidence to suggest that the GES had a positive impact on road safety. According to the other analyses, participation in the GES is associated with a decrease in the odds of collisions and convictions, regardless of whether drivers pass their first attempt of the knowledge test or not. In addition, failing the first road test and/or having demerit points are strong indicators of future collision and conviction involvement. DISCUSSION: Results from this evaluation suggest that the GES has had a protective effect on the safety of senior drivers. PRACTICAL APPLICATIONS: The findings and discussion will help MTO improve the GES program and provide insights to other jurisdictions that have, or are considering, introducing new senior driver programs.

Fatal and serious injuries related to vulnerable road users in Canada.

INTRODUCTION: The goals of this study were to analyze possible trends of fatal and serious injuries related to vulnerable road users in Canada (pedestrians, cyclists and motorcyclists) from 1990 to 2012 and the role of alcohol and drugs in these cases. Drugs have rarely been documented with respect to vulnerable road users. METHOD: The Traffic Injury Research Foundation's National Fatality and Serious Injury Databases and the Public Health Agency of Canada's Canadian Hospitals Injury Reporting and Prevention Program databases were used. Numbers and rates of fatalities and serious injuries among vulnerable road users were analyzed and regression models were used to assess changes over time. RESULTS: The analyses show that while the absolute number of fatalities and the rate per 100,000 population among vulnerable road users may be decreasing, no such trends are apparent when looking at the proportions of these road user fatalities out of all motor-vehicle fatalities. The trend for the proportion of motorcyclist fatalities is significantly increasing (coef.=0.16, p<0.001). The elderly (76years or older) are overrepresented among pedestrian fatalities, and serious injuries (they represent 18.5% of all pedestrian fatalities but only 5.8% of the population), while those 15years or younger are overrepresented among cyclists (they represent 23.3% of cyclist fatalities but 19.5% of the population), and those 16 to 25years old are overrepresented among motorcyclists (27.2% of motorcyclists fatalities and 13.6% of population). Alcohol and drug use among fatally injured vulnerable road users were significant problems, especially among pedestrians. Among fatally injured pedestrians tested for alcohol and drugs, 39.7% and 43.4% tested positive, respectively. CONCLUSIONS: With the promotion of walking and cycling as forms of exercise and the popularity of motorcycling, the safety of vulnerable road users is an important issue. The results corroborate previous research and extend our understanding about the influence of alcohol and drugs in vulnerable road user injuries. PRACTICAL APPLICATIONS: These findings can help better inform prevention and mitigation initiatives for vulnerable road users.

Driving under the influence of alcohol in Cali, Colombia: prevalence and consumption patterns, 2013.

This study's goal was to establish the prevalence of driving under the influence of alcohol (DUI) and alcohol consumption patterns among drivers in Cali, Colombia, in 2013. A cross-sectional study based on a roadside survey using a stratified and multi-stage sampling design was developed. Thirty-two sites were chosen randomly for the selection of drivers who were then tested for blood alcohol concentration (BAC) and asked to participate in the survey. The prevalence of DUI was 0.88% (95% confidence intervals [95% CI] 0.26%-1.49%) with a lower prevalence when BAC was increasing. In addition, a higher prevalence was found during non-typical checkpoint hours (1.28, 95% CI -0.001%-0.03%). The overall prevalence is considered high, given the low alcohol consumption and vehicles per capita. Prevention measures are needed to reduce DUI during non-typical checkpoints and ongoing studies are required to monitor the trends and enable the assessment of interventions.

Multilevel modeling in traffic safety research: two empirical examples illustrating the consequences of ignoring hierarchies.

OBJECTIVES: This commentary illustrates the advantages of multilevel modeling compared to statistical techniques that ignore hierarchies, based on two empirical traffic safety examples. METHODS: The common concept shared by different definitions of multilevel modeling is identified and illustrated. Each definition defines multilevel modeling in its own way but they all refer to hierarchies. Conceptual issues inherently related to hierarchies are then pointed out and illustrated. RESULTS: Broadly speaking there are two important consequences of ignoring a hierarchical structure in the data. The first consequence, underestimation of standard errors, is illustrated with data from an observational study on seatbelt behavior. Two effects that were significant at the 5% level in a single-level model were no longer found to be significant in a two-level model. The single-level model is therefore bound to lead to erroneous conclusions regarding variables that could have an impact on seatbelt use and, ultimately, on increasing the level of traffic safety. The second consequence, related to contextual information, is illustrated with data from a roadside survey on drink driving. Of particular interest is the relationship between Traffic Count, an aggregated level 2 explanatory variable and Odds of drink driving, an individual level 1 dependent variable. CONCLUSIONS: Like every statistical technique, multilevel models should be used with caution and reservation. However, given certain limitations, multilevel modeling is very useful and valuable to traffic safety research.

Designing the European Road Safety Observatory.

The unavailability of consistent traffic accident data and road safety information limits the opportunities to provide target approaches to reduce road crashes. The European commission has decided to meet the demand for this data by establishing a new Road Safety Observatory. The structure and much of the initial content is being developed within the SafetyNet Integrated Project. This paper describes the structure of its key components.

Injuries related to off-road vehicles in Canada.

Off-road vehicles (ORVs; this includes snowmobiles, all-terrain vehicles or ATVs and dirt bikes) were once used primarily for work and travel. Such use remains common in Canada, although their recreational use has also gained popularity in recent years. An epidemiological injury profile of ORV users is important for better understanding injuries and their risk factors to help inform injury prevention initiatives. The Traffic Injury Research Foundation (TIRF) partnered with the Public Health Agency of Canada (PHAC) to analyze the epidemiology of ORV-related injuries. The primary aim was to assess crashes and injuries in Canada, including the extent of alcohol involvement. Secondly, the burden of injury among children and teen ORV drivers in Canada, as well as passengers, was investigated. Descriptive and inferential epidemiological statistics were generated using the following data sources: first, TIRF's National Fatality Database, which is a comprehensive, pan-Canadian, set of core data on all fatal motor vehicle crashes; second, TIRF's Serious Injury Database, which contains information on persons seriously injured in crashes; and, third, PHAC's Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), a surveillance system currently operating in the emergency departments of some pediatric and general hospitals across Canada. Exposure data have been used in the analyzes where available. Between 1990 and 2010, fatality rates increased among ATV and dirt bike operators. The fatality rate among snowmobilers declined during this period. Of particular concern, among fatally injured female ATV users, children aged 0-15 years comprised the highest proportion of any age group at 33.8%. Regarding alcohol use, among fatally injured snowmobile and ATV/dirt bike operators tested for alcohol, 66% and 55% tested positive, respectively. Alcohol involvement in adult ORV crashes remains an important factor. In light of the growing popularity of ORVs, prevention and mitigation measures are required to address this issue.