Research shows that “risky driving behaviour” is not a single dimension, it is more complex than that. Over the last 25 years, researchers have worked to find ways to measure the complex range of factors that contribute to the risks of driving from a human factors perspective. The ultimate purpose is to provide drivers with insight into their behavioural risk to ensure that the training fits addresses the specific elements identified rather than ‘one-size fits all’ training. This research has been instrumental in the development of the Driver Risk Index suite of assessments, with the first set of studies taking place at Aston University in the 1980’s. The Driver Risk Index is now used as part of behaviour based fleet driver safety programmes around the world.
There are four sections in the Driver Risk Index. The behavioural section consists of 5 factors – Aggression, Thrill Seeking, Hazard Monitoring, Fatigue Proneness and Dislike of Driving.
- The Aggression factor deals with risk-taking due to frustration, impatience and hostility to other road users.
- Thrill Seeking assesses enjoyment of risk and how driving behaviour is affected
- The Hazard Monitoring dimension focuses on active attempts to maintain concentration and awareness when driving is difficult.
- Driving Fatigue identifies individual differences in alertness after a long journey.
- Dislike of Driving measures anxiety in response to driving under certain traffic situations.
The variants of the Driver Risk, such as Fleet Driver Risk Index, Police Driver Risk Index, etc., have been the subject of specific research programmes at Cranfield University to investigate how these core factors are reflected in the way drivers at work respond to the particular demands of their job. Each assessment produces a somewhat different profile dependent on the driver’s job role.
Initial research to develop the Driver Stress Inventory used drivers from the UK and US and found that Thrill Seeking and Aggression were linked to dangerous behaviours, especially violations and high speed driving. On the other hand, Hazard Monitoring was associated with safe behaviours (Matthews et al., 1996). Drivers high in Dislike of Driving drove more slowly but made more mistakes when driving. Driving Fatigue was also linked to more mistakes on the road. Older drivers showed a lower-risk profile with lower scores for Aggression, and higher scores for Hazard Monitoring. Thrill Seeking was highest amongst young drivers, but seems to lessen with age. However, some drivers maintain Thrill Seeking tendencies beyond their mid-twenties and behavioural intervention are needed to develop safer habits.
There have been a number of peer-reviewed academic studies on work related driving using the scales from the Driver Risk Index. Two of these studies will now be described.
Oz et al. (2009) looked at four different types of drivers in Turkey – taxi drivers, minibus drivers, large goods vehicle drivers, and private motorists. They reported that Aggression, Hazard Monitoring and Dislike of Driving were related to higher crash rates. High Aggression and Dislike of Driving were both associated with speeding. Minibus drivers were significantly higher in Aggression compared with private motorists probably due to increased driving hours and the frustrations of dealing with passengers and being under time pressure. Higher levels Driving Fatigue were also found amongst professional drivers probably due to longer hours behind the wheel.
In a second study of drivers at work, the Driver Risk Index scales were administered to professional and non-professional drivers in Australia (Desmond and Matthews, 2009) and found that drivers’ Driving Fatigue scores related directly to tiredness and stress after a long drive with a common root cause – coping strategies.
How drivers manage the stressful and fatiguing elements of driving for work are critical to managing risk. Using the Driver Risk Index identifies poor coping strategies that several studies show are related to unsafe driving behaviour. By profiling drivers, we are able to take the first step in providing a specific behaviourally-based intervention to improve safety at work. This approach means that each driver receives an intervention based on their specific needs.