Particular dangers for truck drivers: alcohol, drugs and fatigue

07 Jun 2018 The Human Factor
On analysis of the German accident figures regarding goods transport vehicles, it is striking that the majority of accidents here too can be attributed to human error. In addition to driving-related factors such as failing to keep an adequate distance from the vehicle ahead or driving with excessive speed, alcohol and fatigue are key factors that affect a person’s capability to drive.
As a systematic analysis conducted by Girotto and colleagues in 2013 shows, major differences exist regarding the consumption of alcohol and drugs among truck drivers in the road goods transport sector. This meta-analysis evaluated studies in which drivers personally provided data on their alcohol and drug consumption as well as studies in which biological samples from drivers were tested for alcohol and drugs. In 18 of 23 evaluated questionnaires, drivers most commonly confirmed drinking alcohol.
The 15 studies that analyzed biological samples found that amphetamines, cannabis and cocaine were the most common drugs taken. On average, drivers admitted to consuming alcohol in 54.3 percent of cases, with the range spanning from 9.9 percent (Pakistan) all the way to 91 percent (Brazil). On average, alcohol was verified in 3.6 percent of the biological samples, ranging from a minimum of 0.1 percent (Australia and Norway) to a maximum of 12.5 percent (USA). The average frequency of self-reported amphetamine usage was 29.5 percent, with the range spanning from 0.9 percent (Italy) to 70 percent (Brazil). On average, amphetamines were verified in 8.5 percent of biological samples (0.2 percent in Norway and 82.5 percent in Thailand). On average, drivers personally reported having consumed cannabis in 19.3 percent of investigated cases; cannabis was toxicologically verified in 4.7 percent of biological samples. In addition, other psychotropic substances were found in some of the analyzed studies, including opioids, phentermine, codeine, caffeine-based medicines, antihistamines and benzodiazepine.
The clear differences in the data can be partly attributed to different survey methods. Depending on patterns of consumption, alcohol and other psychotropic substances can be verified in bodily fluids only for up to a few hours or days after they are ingested. Such samples are therefore highly specific with regard to verifying substances, but often result in the actual frequency at which drivers ingest the respective substances being underestimated. In this regard, the self-reporting method enables a long-term insight into the working life of drivers and their consumption of psychotropic substances. But this method also has certain limitations: Respondents might misremember things, tend to provide “socially acceptable” answers or purposely withhold information for fear of any legal consequences. The working conditions in the different countries are also different, for example when it comes to loading and unloading processes, the infrastructure and the technical equipment within vehicles. The authors of a study conducted in Thailand, where amphetamines were verified in 82.5 percent of urine samples, attribute this to a number of factors including excessive working hours of 20–22 hours. They conclude that the ingestion of psychotropic substances is higher when working conditions are poor.