Review of Western Australian drug driving laws

In 2007, the Western Australian Road Traffic Act 1974 was amended to allow for new police enforcement practices designed to reduce the incidence of drug driving. The Road Traffic Amendment (Drugs) Act 2007 made provision for two new offences: driving with the presence of a prescribed illicit drug in oral fluid or blood, and driving while impaired by a drug. The prescribed drugs were methamphetamine, methylenedioxymethamphetamine (MDMA or ecstasy) and delta-9-tetrahydrocannabinol (THC, the psychoactive compound in cannabis). As part of the new laws, statute 72A was inserted into the Act requiring that the Western Australian State Government undertake a review of the amended legislation after 12 months of operation. This report provides a review of the amended legislation and the associated drug driving law enforcement. It includes a process review of the roadside oral fluid testing and drug impaired driving enforcement programs; an analysis of testing, offence detection and legal penalty data pertaining to the first year of operation of the new drug enforcement measures; and a report on consultations with various stakeholders. These form the basis for recommendations on possible improvements to the processes and legislation related to the deterrence of driving after drug use among Western Australian drivers.J.E. Woolley and M.R.J. Baldoc

In-depth research into rural road crashes

This report was produced under an agreement between Transport SA and the Road Accident Research Unit formed in the late 1990s. Due to various delays in the publication of this report, Transport SA has since become the Department for Transport, Energy and Infrastructure and the Road Accident Research Unit has become the Centre for Automotive Safety Research. The report describes a series of 236 rural road crashes investigated between 1 March 1998 and 29 February 2000 in South Australia. Investigations began with immediate attendance at the scene of the crash. The information collected for each crash included: photographs of the crash scene and vehicles involved, video record of the crash scene and vehicles in selected cases, examination of the road environment, a site plan of the crash scene and vehicle movements in the crash, examination and measurements of the vehicles involved, interviews with crash participants, interviews with witnesses, interviews with police, information on the official police report, information from Coroner’s reports, and injury data for the injured crash participants. The report provides an overall statistical summary of the sample of crashes investigated, followed by a detailed examination of the road infrastructure issues contributing to the crashes. This is done on the basis of crash type, with separate sections concerned with single vehicle crashes, midblock crashes and crashes at intersections. A section is also provided that examines the role of roadside hazards in the crashes.Baldock MRJ, Kloeden CN and McLean A

Annual performance indicators of enforced driver behaviours in South Australia, 2007

This report was produced to quantify performance indicators for selected enforced driver behaviours (drink driving, drug driving, speeding and restraint use) in South Australia for the calendar year 2007. The level of random breath testing (RBT) in South Australia in 2007 decreased slightly but remained at a relatively high level. The proportion of tests conducted using mobile RBT continued to increase. The detection rate based on evidentiary testing increased in 2007 to the highest level on record, while the detection rate for screening tests decreased. Detection rates in South Australia were comparable with those in other states. Just over 12,000 drug tests were conducted during 2007, the first full year of random drug testing. Relative to other Australian jurisdictions supplying comparative data, South Australia had the highest testing rate per head of population. Around 24 drivers per 1,000 tested were confirmed positive for at least one of the three prescribed drugs with methylamphetamine the most commonly detected drug. Of the fatally injured drivers who were drug tested in 2007, 25 per cent tested positive for illicit drugs. There was a slight decrease in the number of hours spent on speed detection in 2007. Nevertheless, the total number of speed detections increased, with increases observed for speed camera and red light/speed cameras, the latter most likely due to the expansion of the program. The detection rate (per hour of enforcement and per 1,000 vehicles passing speed cameras) increased by around 30 per cent. Data from systematic speed surveys, introduced in 2007, indicated that travelling speeds on South Australian roads were increasing. The number of restraint offences in 2007 decreased by 14 per cent. Males were charged with more restraint offences and were more likely to be unrestrained in fatal and serious injury crashes than females, indicating that males remain an important target for restraint enforcement. The 2007 publicity campaign focused on the consequences of not using restraints rather than increasing the perceived risk of detection.LN Wundersitz, K Hiranandani, MRJ Baldoc

Robust point correspondence applied to two and three-dimensional image registration

Accurate and robust correspondence calculations are very important in many medical and biological applications. Often, the correspondence calculation forms part of a rigid registration algorithm, but accurate correspondences are especially important for elastic registration algorithms and for quantifying changes over time. In this paper, a new correspondence calculation algorithm, CSM (correspondence by sensitivity to movement), is described. A robust corresponding point is calculated by determining the sensitivity of a correspondence to movement of the point being matched. If the correspondence is reliable, a perturbation in the position of this point should not result in a large movement of the correspondence. A measure of reliability is also calculated. This correspondence calculation method is independent of the registration transformation and has been incorporated into both a 2D elastic registration algorithm for warping serial sections and a 3D rigid registration algorithm for registering pre and postoperative facial range scans. These applications use different methods for calculating the registration transformation and accurate rigid and elastic alignment of images has been achieved with the CSM method. It is expected that this method will be applicable to many different applications and that good results would be achieved if it were to be inserted into other methods for calculating a registration transformation from correspondence

Bed shear stress measurements in dam break and swash flows

A novel shear plate was used to make direct bed shear stress measurements in laboratory dam break and swash flows on smooth, fixed, impermeable beds. The pressure gradient due to the slope of the fluid free-surface across the plate was measured using pressure transducers. Surface elevation was measured at five locations using acoustic displacement sensors. Flow velocity was measured using an Acoustic-Doppler Velocimeter and calculated using the ANUGA inundation model. The measured bed shear stress at the dam break fluid tip for an initially dry, horizontal bed was close to twice that estimated using steady flow theory. The temporal variation of swash bed shear stress showed a large peak in landward directed stress at the uprush tip, followed by a rapid decay throughout the uprush flow interior. The peak seaward directed stress during the backwash phase was less than half that measured in the uprush. Close to the still water line, in the region of bore collapse and at the time of initial uprush, favourable pressure gradients were measured. In the lower swash region predominately weak adverse pressure gradients were measured

Self-regulation of driving and its relationship to driving ability among older adults

Although it is known that older drivers limit their driving, it is not known whether this self-regulation is related to actual driving ability. A sample of 104 older drivers, aged between 60 and 92, completed a questionnaire about driving habits and attitudes. Ninety of these drivers also completed a structured on-road driving test. A measure of self-regulation was derived from drivers’ self-reported avoidance of difficult driving situations. The on-road driving test involved a standard assessment used to determine fitness to drive. Of the 90 participants who completed the driving assessment, 68 passed the test, eight passed but were recommended to have driving lessons and 14 failed. Driving test scores for the study were based on the number of errors committed in the driving tests, with weightings given according to the seriousness of the errors. The most commonly avoided difficult driving situations were parallel parking and driving at night in the rain, while the least avoided situation was driving alone. Poorer performance on the driving test was not strongly related to overall avoidance of difficult driving situations. Stronger relationships were found between driving ability and avoidance of specific difficult driving situations. These specific driving situations were the ones in which the drivers had low confidence and that the drivers were most able to avoid if they wished to. These results may reflect a tendency for those with poorer driving ability to lose confidence in their driving, and begin to avoid difficult driving situations. However, there are a number of situations that drivers find difficult to avoid.M.R.J. Baldock, J.L. Mathias, A.J. McLean, A. Bernd

Review of the literature on cannabis and crash risk

A review of the literature published prior to 2005 concerning cannabis and road crash involvement was conducted, with emphasis given to studies documenting the relative crash risk associated with driving after use of cannabis. Case-control studies that have been conducted into cannabis and road crashes have been characterised by methodological flaws that make the interpretation of the results difficult. Partly as a response to the difficulty of conducting case-control studies, some researchers have used culpability studies to determine whether cannabis use contributes to crash involvement. However, as for case-control studies into cannabis and crash involvement, many culpability studies are difficult to interpret because of methodological problems. There have been two recent Australian studies that have analysed the relationship between THC (tetrahydrocannabinol - the psychoactive component of cannabis) measured in the blood and crash culpability. These two studies produced contradictory results. In summary, the risk of crash involvement associated with driving under the influence of cannabis remains to be determined. To resolve the issue, it is necessary to conduct a case-control study similar to those that have been conducted for alcohol. That is, it is necessary to compare the incidence of cannabis in crash-involved drivers with the incidence in non-crash-involved drivers matched for potential confounding factors, such as age, gender, time of day, day of week, and direction of travel.MRJ Baldoc

Cannabis and the Risk of Crash Involvement

Drugs have long been a focus of law enforcement in Australia but recent legislation in a number of Australian states now requires routine drug testing of drivers (testing for cannabis and methamphetamine), with the stated aim of reducing road crashes. Such legislation is justified if these drugs are known to increase the risk of crashing. Literature concerning cannabis and road crash involvement was reviewed, with emphasis given to studies documenting the relative crash risk associated with driving after use of cannabis. All case-control and culpability studies of cannabis and crashes have been characterised by methodological flaws that make interpretation of the results difficult. Two recent Australian studies analysed the relationship between tetrahydrocannabinol (THC, the psychoactive component of cannabis) measured in the blood and crash culpability. These two studies produced contradictory results. In summary, the risk of crash involvement associated with driving under the influence of cannabis remains to be determined.Matthew Baldoc

Best practice criteria in practical driving tests of medically referred drivers

Section 80 of the Motor Vehicles Act empowers the Registrar of Motor Vehicles to require drivers to undergo a practical test of their driving ability. These practical driving assessments (PDAs) are chiefly administered by Safety Education Officers (SEOs) employed by the Department for Transport, Energy and Infrastructure. Given the importance of licensure for a person’s mobility and independence, PDAs must be of an excellent standard, producing valid and reliable outcomes for those who are assessed. Specifically, they must be structured so that they reliably produce the appropriate recommendations regarding each driver’s medical fitness to hold a driver’s licence. This report provides a review of the literature published prior to 2006 concerned with the best methods for assessing medical fitness to drive. This enables comparisons between the methods used in South Australia and the best-practice methods described in the literature, which, in turn, enables the identification of possible improvements that could be made to the South Australian system. Possible improvements to South Australian practice include the greater involvement of occupational therapists in the assessment process, the use of an interview and functional testing prior to the on-road test, the use of a dual controlled vehicle provided by the testing agency, a longer duration of the on-road test, the presence of a third party in the vehicle during an on-road test to take detailed scoring notes, and the provision of counselling and advice when necessary at the completion of an assessment.MRJ Baldoc