In recent years the introduction of airbags, ABS braking systems, traction control and other safety features has undoubtedly made driving safer by reducing the chances of the driver being involved in a collision. While these developments have clearly increased the safety ratings of the vehicles we drive, do they actually make our driving safer?
A great deal of research has examined how our driving changes when additional safety features are introduced. One of the first researchers to suggest this pattern of driving behaviour was Gerald Wilde in the 1980’s, who proposed the ‘risk homoeostasis’ theory, more commonly referred to as “risk compensation”.
According to this hypothesis, each driver has a certain level of risk that they are willing to take when driving and this level is maintained regardless of how many safety features the vehicle has. Essentially, if someone is prepared to drive in a risky manner, they will increase the riskiness of their driving when they are in a vehicle with many safety features.
Since then, research has examined how people adjust their driving behaviours in response to a wide range of different safety devices.
In a series of studies throughout the 1990’s Fridulv Sagberg and colleagues from the Institute of Transport Economics examined how driving behaviours change when safety devices are introduced. In one study they considered how the use of ABS and airbags influenced the driving behaviours of taxi drivers. One of the key differences they found was that seatbelt usage decreased and drivers tended to adopt close following behaviours when the taxi was fitted with ABS. In another study the research group found that improved street lighting was associated with faster driving speeds and reduced concentration.
One interesting development of the risk compensation hypothesis is that drivers adapt their behaviours differently for different safety devices. An example would be ABS, a dynamic device designed to reduce the risk of a collision occurring, as opposed to non dynamic devices designed to reduce the risk of injury, such as airbags.
Sagberg suggested that people are far more likely to engage in risk compensation behaviours when driving a vehicle with collision avoidance mechanisms, so increasing the riskiness of their driving. In contrast, no compensation or change in the riskiness of their driving seems to occur when driving a vehicle with injury-reducing devices. This seems to suggest that people are willing to risk having a crash, but not to be injured as a result.
One important point to remember about risk compensation behaviours is that they are not a conscious decision. People do not decide to drive in a riskier manner just because they have air bags and ABS brakes. Instead, people unconsciously adjust their acceptable levels of risk according to the safety features of the vehicle they are driving.
To improve safety and reduce risk when driving it is important to understand how driving styles might adjust according to the vehicle being driven. Regardless of how many safety features might be installed, the most important and effective source of safety is the driver. Awareness of the risks that you take when driving and techniques that can be adopted to reduce risk taking is still clearly the best way to avoid a collision.
Dr Victoria Bourne (BA Hons, DPhil)
Consultant to Driving Risk Management Limited
