Interaction between socio-demographic characteristics: Traffic rule violations and traffic crash history for young drivers

Young drivers’ high traffic violation involvement rate and significant contribution to traffic crashes compared to older drivers creates the need for detailed analyses of factors affecting young drivers’ behaviors. This study is based on survey data collected from 2,057 18–29 year old young adults. Data were collected via face-to-face questionnaire surveys in four different cities in Turkey. The main objective of this study is to identify the relationship between socio-demographic characteristics, traffic rule violations, and traffic crashes among young drivers. Four main traffic rule violations are examined: red light violations, seat belt violations, speeding, and driving under the influence of alcohol, which are decisive in determining driving behavior and traffic crashes. The survey investigates the socio-demographic characteristics, traffic rule violation behavior and traffic crash histories of young adults. Four hypothetical scenarios were prepared for each traffic rule violation and data from the scenarios were modeled using the ordered probit model. Significant variables affecting each traffic rule violation are stated. Finally, significant variables that interact with crash involvements were investigated with binary logit models. According to the data analysis, 23.9% of drivers stated that they were involved in at least one traffic crash within the last three years. This crash rate increases to 38.3% for those who received at least one traffic citation/violation in last three years and peaks to 47.4% for those who were fined for seat belt violations in last three years.     

Risk factors associated with traffic violations and accident severity in China

With the recent economic boom in China, vehicle volume and the number of traffic accident fatalities have become the highest in the world. Meanwhile, traffic accidents have become the leading cause of death in China. Systematically analyzing road safety data from different perspectives and applying empirical methods/implementing proper measures to reduce the fatality rate will be an urgent and challenging task for China in the coming years. In this study, we analyze the traffic accident data for the period 2006–2010 in Guangdong Province, China. These data, extracted from the Traffic Management Sector-Specific Incident Case Data Report, are the only officially available and reliable source of traffic accident data (with a sample size >7000 per year). In particular, we focus on two outcome measures: traffic violations and accident severity. Human, vehicle, road and environmental risk factors are considered. First, the results establish the role of traffic violations as one of the major risks threatening road safety. An immediate implication is: if the traffic violation rate could be reduced or controlled successfully, then the rate of serious injuries and fatalities would be reduced accordingly. Second, specific risk factors associated with traffic violations and accident severity are determined. Accordingly, to reduce traffic accident incidence and fatality rates, measures such as traffic regulations and legislation—targeting different vehicle types/driver groups with respect to the various human, vehicle and environment risk factors—are needed. Such measures could include road safety programs for targeted driver groups, focused enforcement of traffic regulations and road/transport facility improvements. Data analysis results arising from this study will shed lights on the development of similar (adjusted) measures to reduce traffic violations and/or accident fatalities and injuries, and to promote road safety in other regions.     

Road traffic accidents among alcohol-dependent patients: the effect of treatment

It is well known that driving under the influence of alcohol increases the risk of traffic accidents. Alcohol-dependent patients are responsible for two-thirds of motor vehicle crashes involving alcohol. Studies carried out on the general population have shown a relation between alcohol dependence and traffic accidents. The aim of the study is to analyse the effect on traffic accidents of treatment of patients with alcohol-related problems. To do so, the prevalence of traffic problems in a sample of patients with a diagnosed dependence on alcohol was assessed for three periods: during their lifetime, in the year preceding the start of treatment and over the year of treatment. A prospective study was carried out of 176 patients (147 males, 29 females; mean age 42.9 years) diagnosed as alcohol dependent according to the DSM-IV criteria in three alcoholic treatment centres in Castilla y León, Spain. 36.9% of the alcohol-dependent patients had had some kind of traffic problem during their life and 8.5% in the year prior to starting treatment. The most frequent problem was positive breath tests, followed by accidents with damage to the vehicle. Sixty-nine of the 176 patients were still receiving treatment after a year. The prevalence of traffic problems among those patients who followed treatment for 1 year (4.3%) was lower than in the year before treatment (15.9%). The study showed that the treatment is also effective in reducing traffic problems.     

The relationship between social capital and traffic law violations: Israeli Arabs as a case study

Social aspects of a community may be correlated with driver's involvement in road traffic accidents. This study focused on examining this association in the context of the social capital theory. A survey of 600 Arab drivers living in 19 towns and villages was conducted using a face-to-face interview. Structural equation modeling was applied to explore paths of associations between the model components. Most of the proposed relationships in the path model were found to be significant, where the model explained 37% of the variation. The results indicate that only volunteering and reciprocity have direct correlations with traffic law violations. While the other correlations (except political involvement), were mediated by attitudes toward traffic laws violation.     

Traffic violations in Guangdong Province of China: Speeding and drunk driving

The number of speeding- and drunk driving-related injuries in China surged in the years immediately preceding 2004 and then began to decline. However, the percent decrease in the number of speeding and drunk driving incidents (decrease by 22%) is not proportional to the corresponding percent decrease in number of automobile accident-related injuries (decrease by 47%) from the year 2004 to 2010 (Traffic Management Bureau, Ministry of Public Security, Annual Statistical Reports on Road Traffic Accidents). Earlier studies have established traffic violations as one of the major risks threatening road safety. In this study, we examine in greater detail two important types of traffic violation events, speeding and drunk driving, and attempt to identify significant risk factors associated with these types of traffic violations. Risk factors in several different dimensions, including driver, vehicle, road and environmental factors, are considered. We analyze the speeding (N = 11,055) and drunk driving (N = 10,035) data for the period 2006–2010 in Guangdong Province, China. These data, obtained from the Guangdong Provincial Security Department, are extracted from the Traffic Management Sector-Specific Incident Case Data Report and are the only comprehensive and official source of traffic accident data in China. Significant risk factors associating with speeding and drunk driving are identified. We find that several factors are associated with a significantly higher probability of both speeding and drunk driving, particularly male drivers, private vehicles, the lack of street lighting at night and poor visibility. The impact of other specific and unique risk factors for either speeding or drunk driving, such as hukou, road type/grades, commercial vehicles, compulsory third party insurance and vehicle safety status, also require particular attention. Legislative or regulatory measures targeting different vehicle types and/or driver groups with respect to the various driver, vehicle, road and environmental risk factors can subsequently be devised to reduce the speeding and drunk driving rates. As the country with the highest number of traffic accident fatalities in the world, applying these findings in workable legislation and enforcement to reduce speeding and drunk driving rates will save tens of thousands of lives.     

Identifying factors that predict persistent driving after drinking,unsafe driving after drinking,and driving after using cannabis among young adults

The main aim of this study was to identify adolescent/young adulthood factors that predicted persistent driving after drinking, persistent unsafe driving after drinking, and persistent cannabis use and driving among young adults. It was a longitudinal study of a birth cohort (n=933, 474 males and 459 females) and was based on data collected at ages 15, 18, 21 and 26 years. At each of these ages members of the cohort attended the research unit for a personal interview by a trained interviewer, using a standardised questionnaire. For this study, the data for the outcome measures (persistent driving after drinking, persistent unsafe driving after drinking, and persistent driving after using cannabis) were obtained at ages 21 and 26 years. The main explanatory measures were collected at ages 15, 18, 21 years and included demographic factors (academic qualifications, employment, parenting); personality measures; mental health measures (substance use, cannabis dependence, alcohol dependence, depression); anti-social behaviour (juvenile arrest, aggressive behaviour, court convictions); early driving behaviour and experiences (car and motorcycle licences, traffic crashes).The analyses were conducted by gender. The results showed that females who persisted in driving after drinking (13%, n=61) were more likely than the others to have a motorcycle licence at 18. The males who persisted in driving after drinking (28%, n=135) were more likely than the other males to have some school academic qualifications and to be employed at age 26. Compared to the other males, those who persisted in unsafe driving after drinking (4%, n=17) were more likely to be aggressive at 18 and alcohol dependent at 21. Only six (1%) females persisted in unsafe driving after drinking so regression analyses were not conducted for this group. For persistent driving after using cannabis, the univariate analyses showed that females who persisted with this behaviour tended to have high substance use at 18, cannabis dependence at 21, police contact as a juvenile, and to be a parent at 21. For this group, because of the small numbers (3%, n=13) multivariate analyses were not appropriate. For the males who persisted in driving after using cannabis (14%, n=68) a wide range of variables were significant at the univariate stage. The multivariate analysis showed that the most important factors were dependence on cannabis at 21, at least one traffic conviction before 21, a non traffic conviction before 18, and low constraint at 18. CONCLUSION: These results show different characteristics were associated with persistence in each of these outcome behaviours. This indicates that different approaches would be required if intervention programmes were to be developed to target these behaviours.     

The effects of cannabis and alcohol on simulated arterial driving: Influences of driving experience and task demand

This study compared the effects of three doses of cannabis and alcohol (placebo, low and high doses), both alone and in combination, on the driving performance of young, novice drivers and more experienced drivers. Alcohol was administered as ethanol (95%) mixed with orange juice in doses of approximately 0, 0.4 and 0.6 g/kg. Cannabis was administered by inhalation of smoke from pre-rolled cannabis cigarettes (supplied by the National Institute of Drug Abuse, USA). Active cigarettes contained 19 mg delta-9-THC. Using a counterbalanced design, the simulated driving performance of 25 experienced and 22 inexperienced drivers was tested under the nine different drug conditions in an arterial driving environment during which workload was varied through the drive characteristics as well as through the inclusion of a secondary task. High levels of cannabis generally induced greater impairment than lower levels, while alcohol at the doses used had few effects and did not produce synergistic effects when combined with cannabis. Both cannabis and alcohol were associated with increases in speed and lateral position variability, high dose cannabis was associated with decreased mean speed, increased mean and variability in headways, and longer reaction time, while in contrast alcohol was associated with a slight increase in mean speed. Given the limitations of the study, it is of great interest to further explore the qualitative impairments in driving performance associated with cannabis and alcohol separately and how these impairments may manifest in terms of crash characteristics.     

Factors associated with alcohol and drug use among traffic crash victims in southern Brazil

Objective

To investigate the prevalence of and factors associated with alcohol- or drug-related traffic crashes (TC) in a sample of TC victims who were admitted to the two emergency rooms of Porto Alegre in southern Brazil.

Methods

A cross-sectional study with consecutive samples was used. Victims of non-fatal TCs (as drivers, passengers or pedestrians) who had presented at emergency rooms during the 45 days of data collection were selected. Subjects participated in a structured interview, were breathalyzed and underwent salivary drug testing. A multinomial logistic regression model was used to verify factors associated with alcohol or drug use.

Results

Of the 609 victims who participated in the interview, 72% were male, and the median age was 29 years (interquartile range 23.0–40.0 years). The drivers were mostly men (p < 0.001), with a higher binge drinking rate (p = 0.003) and marijuana use (p = 0.005) than seen in pedestrian and passengers. The prevalence of a positive blood alcohol concentration (BAC) ranged from 7.8% among the drivers to 9.2% among the pedestrians (p = 0.861), and the cannabis prevalence was 13.3% among the drivers. The variables associated with an alcohol-related accident were binge drinking in the prior 12 months (OR 2.4; CI 95% 1.1–5.1) and coming from a party/bar (OR 8.7; CI 95% 2.8–26.7). Alcohol abuse or dependence increased by 5.2-fold the chance of another substance-related TC.

Conclusion

The large number of individuals found in TC-related emergency room visits in a short time frame is evidence of the Brazilian epidemic of TC. The data showed that alcohol abuse or dependence also increases the risk of intoxication by other drugs, and they point to alcohol and drug use as a major problem requiring specific TC-related public policies and law enforcement.     

Cannabis use and traffic accidents in a birth cohort of young adults

Objective: to examine linkages between cannabis use and traffic accident risks in a birth cohort of 907 young New Zealanders studied from 18 to 21 years. Methods: during the course of a 21-year longitudinal study of a birth cohort of 907 New Zealand born children information was gathered on (a) annual frequency of cannabis use over the period from 18 to 21 years; (b) annual rates of traffic accidents during the period 18–21 years; (c) measures of driver behaviours and characteristics. The association between cannabis use and traffic accident risk was examined among the 907 sample members who reported driving a motor vehicle between the ages of 18 and 21 years. Results: there were statistically significant relationships between reported annual cannabis use and annual accident rates. This association was present only for ‘active’ accidents in which driver behaviours contributed to the accident; those using cannabis more than 50 times per year had estimated rates of active accidents that were 1.6 (95% CI 1.2–2.0) times higher than the rate for non-users. However, statistical control for driver behaviours and characteristics related to cannabis use (drink driving behaviour; risky/illegal driving behaviours; driver attitudes; gender) eliminated the association between cannabis use and traffic accident risks. Conclusions: although cannabis use was associated with increased risks of traffic accidents among members of this birth cohort, these increased risks appear to reflect the characteristics of the young people who used cannabis rather than the effects of cannabis use on driver performance.     

Drug use and the severity of a traffic accident

Several studies have showed that driving under the influence of alcohol and/or certain illicit or medicinal drugs increases the risk of a (severe) crash. Data with respect to the question whether this also leads to a more severe accident are sparse. This study examines the relationship between the use of alcohol, illicit drugs and/or medicinal drugs and the severity of an accident within a group of drivers that were involved in a crash in The Netherlands. Blood samples of 993 drivers, collected in the period from October 1998 through September 1999, were linked to accident characteristics as available from the National Transport Research Centre. The outcome measure was the severity of the accident. An accident was considered severe when the accident had resulted in hospital admission or death. All the blood samples obtained after the accident were screened for the presence of alcohol, illicit drugs (opiates, amphetamines and amphetamine-like substances, cocaine and metabolites, methadone, cannabinoids) and medicinal drugs (benzodiazepines, barbiturates and tricyclic antidepressants). The strength of the associations between exposure to the different classes of alcohol/drugs/medicines and the severity of the accident was evaluated using logistic regression analysis and were expressed as odds ratios (OR), adjusted for age, gender, time of the day, day of the week and urban area. The most frequently detected drugs were cannabinoids, benzodiazepines and cocaine. Our results showed no clear association between the use of alcohol, illicit drug and/or medicinal drug use and the severity of the accident. Given the process of obtaining blood samples from drivers involved in accidents and the retrospective nature of the study, we cannot rule out the occurrence of selection bias. Therefore, our findings need further confirmation.     

News, music videos and action movie exposure and adolescents' intentions to take risks in traffic

This study explored the relationship between adolescents' viewing of specific television genres (action movies, news and music videos) and the intention to take risks in traffic. Participants were 2194 adolescent boys and girls who completed a questionnaire on television viewing, risk perception and the intention to speed and drive after consuming alcohol. As hypothesized, more news viewing was associated with a higher perceived risk of drunk driving and speeding. More music video viewing, on the other hand, was negatively associated with the assessment of the dangers of speeding and driving under the influence of alcohol. Girls regarded speeding and drunk driving as more dangerous than boys did. Contrary to our hypotheses, action movie viewing did not make a significant contribution to our models. Both news and music video viewing were indirectly, via risk perception, related to the intention to drive risky. The more dangerous a particular behavior was perceived to be, the less likely respondents intended to exhibit this behavior in the future.     

Alcohol, psychoactive drugs and fatal road traffic accidents in Norway: a case-control study

A case–control study was conducted on 204 drivers fatally injured in road traffic accidents in south-eastern Norway during the period 2003–2008. Cases from single vehicle accidents (N = 68) were assessed separately. As controls, 10 540 drivers selected in a roadside survey in the same geographical area during 2005–2006 were used. Blood samples were collected from the cases and oral fluid (saliva) samples from the controls. Samples were analysed for alcohol, amphetamines, cannabis, cocaine, opioid analgesics, hypnotics, sedatives and a muscle relaxant; altogether 22 psychoactive substances. Equivalent cutoff concentrations for blood and oral fluid were used. The risk for fatal injury in a road traffic accident was estimated using logistic regression adjusting for gender, age, season of the year, and time of the week. The odds for involvement in fatal road traffic accidents for different substances or combination of substances were in increasing order: single drug < multiple drugs < alcohol only < alcohol + drugs. For single substance use: medicinal drug or THC < amphetamine/methamphetamine < alcohol. For most substances, higher ORs were found when studying drivers involved in single vehicle accidents than for those involved in multiple vehicle accidents, but confidence intervals were wider.     

Crash risk and aberrant driving behaviors among bus drivers: The role of personality and attitudes towards traffic safety

Several studies have shown that personality traits and attitudes toward traffic safety predict aberrant driving behaviors and crash involvement. However, this process has not been adequately investigated in professional drivers, such as bus drivers. The present study used a personality–attitudes model to assess whether personality traits predicted aberrant self-reported driving behaviors (driving violations, lapses, and errors) both directly and indirectly, through the effects of attitudes towards traffic safety in a large sample of bus drivers. Additionally, the relationship between aberrant self-reported driving behaviors and crash risk was also assessed.     

Comparing the cost of alcohol-related traffic crashes in rural and urban environments

Context

Existing studies have identified that, although to a lesser extent than individual factors such as males and young people, rural (compared to urban) communities represent a disproportionately high-risk of alcohol-related traffic crashes (ARTCs). To date, however, few studies have attempted to apply different costs to alcohol crashes of different severity, to provide more precise, and practically useful, data on which to base public health policy and intervention decisions.

Objective

The aim of this study is to quantify the per capita prevalence and differential costs of alcohol crashes of different levels of severity to determine the extent to which urban and rural geographical areas may differ in the costs attributable to ARTCs.

Design

A cross-sectional analysis of alcohol-related traffic crash and costs data from 2001 to 2007.

Setting and participants

Data from New South Wales, Australia.

Main outcome measures

Modified routinely collected traffic accident data to which costs relevant to alcohol crashes of different severity are applied.

Results

Although the rate per 10,000 population of alcohol-related crashes is 1.5 times higher in rural, relative to urban, communities, the attributable cost is four times higher, which largely reflects that rural alcohol-fatalities are seven to eight times more prevalent and costly.

Conclusions

Given that per capita alcohol-related fatal crashes in rural areas account for a disproportionately large proportion of the harms and costs associated with alcohol-related traffic crashes, the cost-effectiveness of public health interventions and public policy initiatives should consider the relative extent of ARTC-harm in rural versus urban communities.     

The development and application of a proxy measure of alcohol-related traffic crashes for rural communities

Context

To date, no studies have adequately examined whether community-level, rather than individual-level, characteristics, are associated with high rates of alcohol-related traffic crashes (ARTC).

Objective

This study aims to identify a proxy measure of ARTC most appropriate to rural communities in New South Wales (NSW), Australia, and to identify community characteristics that predict higher rates of ARTC.

Methods

ARTC (2001–2007) incident data from 20 rural communities in NSW were obtained. Cost data were applied to take account of ARTCs of different severity.

Results

The method used to define a proxy measure of ARTCs for NSW generally was found to be inadequate when applied to local communities within NSW: specifically, two time periods were found to be alcohol-related for local communities only and seven time periods were found to be non-alcohol-related for local communities only. Applying a community-specific proxy measure of ARTCs to 20 communities identified substantial variation in ARTC cost-ratios, ranging from 1.20 to 0.15. Higher cost-ratios were statistically significantly predicted by the proportion of residents who were male and less than 25 years.

Conclusions

Proxy measures of ARTCs represent an ideal method of utilising routinely collected data to identify specific types of ARTCs that are most relevant to a defined community, identify community-specific factors associated with higher rates of ARTCs and measure the impact of interventions tailored to those risk factors. Such measures ought to be community-specific because these results suggest national or provincial-level definitions are not necessarily directly applicable to local communities. These results show substantial variability between communities in their rates of ARTC and identify communities with higher proportions of young males as being at increased risk.     

Comparison of driving simulator performance with real driving after alcohol intake: A randomised,single blind,placebo-controlled,cross-over trial

The purpose of this study was to establish and validate a driving simulator method for assessing drug effects on driving. To achieve this, we used ethanol as a positive control, and examined whether ethanol affects driving performance in the simulator, and whether these effects are consistent with performance during real driving on a test track, also under the influence of ethanol. Twenty healthy male volunteers underwent a total of six driving trials of 1 h duration; three in an instrumented vehicle on a closed-circuit test track that closely resembled rural Norwegian road conditions, and three in the simulator with a driving scenario modelled after the test track. Test subjects were either sober or titrated to blood alcohol concentration (BAC) levels of 0.5 g/L and 0.9 g/L. The study was conducted in a randomised, cross-over, single-blind fashion, using placebo drinks and placebo pills as confounders. The primary outcome measure was standard deviation of lateral position (SDLP; “weaving”). Eighteen test subjects completed all six driving trials, and complete data were acquired from 18 subjects in the simulator and 10 subjects on the test track, respectively. There was a positive dose–response relationship between higher ethanol concentrations and increases in SDLP in both the simulator and on the test track (p < 0.001 for both). In the simulator, this dose–response was evident already after 15 min of driving. SDLP values were higher and showed a larger inter-individual variability in the simulator than on the test track. Most subjects displayed a similar relationship between BAC and SDLP in the simulator and on the test track; however, a few subjects showed striking dissimilarities, with very high SDLP values in the simulator. This may reflect the lack of perceived danger in the simulator, causing reckless driving in a few test subjects. Overall, the results suggest that SDLP in the driving simulator is a sensitive measure of ethanol impaired driving. The comparison with real driving implies relative external validity of the simulator.     

Driving under the influence of cannabis: Links with dangerous driving, psychological predictors, and accident involvement

Driving under the influence of cannabis (DUIC) has become a growing concern. Studies investigating the impact of DUIC on traffic safety have shown evidence that, during the acute period of cannabis intoxication, cannabis diminishes driving faculties and is associated with an elevated risk of collision. However, DUIC drivers seem to exhibit a general reckless driving style that may contribute to an over-estimation of DUIC-related collisions among this group. In this study, we investigated DUIC drivers with respect to self-reported dangerous driving habits (e.g., risky driving, aggressive driving and negative emotional driving), behaviours observed in a driving simulator, psychological predictors and crash involvement. Results suggest that DUIC is associated with self-reported and observed risky driving and negative emotional driving. We also found that sensation seeking and impulsivity are independent psychological predictors of DUIC. Finally, a trend suggests that self-reported DUIC is associated with an increased risk of being involved in a car accident, after controlling for dangerous driving and demographic variables. Implications for interventions are discussed.     

Disabilities resulting from traffic injuries in Barcelona, Spain: 1-year incidence by age, gender and type of user

The purpose of this study was to examine the 1-year incidence of disabilities resulting from traffic injuries among the population of Barcelona (Spain), as well as its distribution by age, gender and type of motor-vehicle user, taking into account different exposure criteria. This is a population-based cross-sectional study; subjects were all cases (n=4080) having undergone a medical examination for a traffic injury having occurred in 1993 resulting in a disability among residents in the area of Barcelona. Subjects were considered to have suffered a disability as a result of an injury if they were prevented from carrying out their normal activities for a period of 2 days or more. In 1993, the cumulative incidence rate of disability was 237.9 cases per 100 000 inhabitants, higher for men (287.1) than for women (193.9). The 20–24 year age group showed the highest incidence of disability (607.5). The rate of incidence of disability was 95.5 per 100 000 inhabitants among occupants of two wheeled vehicles, 87.7 among car occupants and 39.9 in pedestrians. When length of exposure to traffic was taken into account, the incidence rate of disability for residents aged >14 years was 1.09 per 100 000 hours per person per year, similar for both sexes. This study represents a first attempt to use population-based health data to evaluate the incidence of disabilities due to traffic injuries. The results allow the identification of the groups with the greatest risk and who contribute the most to disabilities resulting from injuries, especially young users of two-wheeled motor vehicles.     

Predictors of driving after alcohol and drug use among adolescents in Valencia (Spain)

Background

Driving under the influence of alcohol and drugs has been identified as a risk factor for road traffic crashes. We have assessed the prevalence and predictor factors for driving after alcohol and drug use by adolescents.

Methods

A cross-sectional survey involving 11,239 students aged 14–18 years from 252 private and public schools in the Valencia region of Spain was conducted. The prevalence and predictors of driving after alcohol use, alcohol and drug use, or drug use during the previous 6 months were measured.

Results

Of the students who reported driving (20%), 45.1% indicated driving after alcohol and drug use. The consumption of various drugs was higher among students who drove a vehicle compared with those who did not. The likelihood of driving after consuming alcohol, or alcohol and drugs, increased in line with the number of standard drink units per week, reports of any lifetime alcohol- or drug-related problems, and poor family relationship. In addition, masculine gender and early alcohol use increased the likelihood of driving after consuming alcohol.

Conclusions

Driving after alcohol and drug use is quite prevalent among adolescents in the Valencia region of Spain. There is a need for implementation of targeted policies for adolescents. This should focus on education and information on alcohol/drug use and driving.     

Random breath testing in Queensland and Western Australia: Examination of how the random breath testing rate influences alcohol related traffic crash rates

In this paper we explore the relationship between monthly random breath testing (RBT) rates (per 1000 licensed drivers) and alcohol-related traffic crash (ARTC) rates over time, across two Australian states: Queensland and Western Australia. We analyse the RBT, ARTC and licensed driver rates across 12 years; however, due to administrative restrictions, we model ARTC rates against RBT rates for the period July 2004 to June 2009.