Topic letter 24

Using a hands-free phone while driving, why is it dangerous?

Shell and DSM have introduced life saving rules, a set of 12 doís and doníts intended to protect the lives of their personnel. Shell claims that fatalities within the company have decreased since the introduction of these rules. A salient detail is that many of these rules relate to travel. Apparently one of the most dangerous aspects of working in a chemical company is that you sometimes have to use public roads. One of the 12 rules relates to the use of hands-free phones while driving. This is forbidden under penalty of dismissal. Why have these companies introduced this rule and why does official legislation differ in this matter?

Whatís the difference between phoning and talking?

The first question is why is phoning more dangerous than talking to a passenger? Unfortunately, there is no scientific evidence available on this matter, but I do have a hypothesis. What happens in general when somebody receives a call on the mobile phone? The first thing we can observe is that this person has a tendency to become distracted, not only figuratively but also literally. There is an unconscious tendency to abandon companionship while phoning. Good communication demands that you have to put yourself in somebody elseís position. The more you are preoccupied with your own position, the harder it is to understand others. The consequence of phoning while driving is that you are mentally elsewhere and less focused on the here and now situation. This principle creates an essential difference between phoning and talking to somebody sitting next to you.

Our brain follows our attention.

Our senses are so well developed that we constantly receive far more stimuli than we can digest. We constantly have to filter our information and one way of filtering is based on itís the relevance to the moment. If we are mentally somewhere else, the input from the present situation becomes less important. This filtering process has been scientifically verified while using a traffic simulator. This is especially true with regards to sounds and also stimuli that are perceived at the corners of our eyes (traffic coming from aside). This information is processed by the brain at a lower level of importance. In comparison to talking to our passenger we pay less attention to directly available information while using our mobile phone.

Lack of awareness

The filtering of information is an autonomous and unconscious process. We donít notice it. The effect of using a hands-free phone is similar to the effect of drinking some alcohol. Experiments in the simulator show that the effect is comparable to that of four glasses of alcohol. Besides that, both of these reduce our sensitivity to feedback on our behavior. Drivers who are using a hands-free phone donít notice their difficulty in maintaining a straight line. Without feedback it is difficult to estimate how well we are driving and to adjust our behavior to the situation. We may not even learn from it for a next time.

The danger of overestimation

Itís no secret that we sometimes have an unjustified self-image. We call this an attribution failure. We think we possess attributes that we actually donít have. A lot of people suffer from a chronic overestimation of their safety behavior. Many of us are convinced that they belong to the top 50% of safe drivers. If we were less confident, we would probably be more sensitive to deviations from normal driving patterns. All these factors combine to make driving while using a hands-free phone a dangerous activity resulting in many fatalities.

The role of the government

In many countries it is forbidden by law to use a handheld phone while driving. In some countries there are restrictions on using hands-free phones but only for novice drivers. However, a distinction between handheld and hands-free phoning has never been proven to be relevant. On the contrary, research shows that all phoning while driving is dangerous. Politicians seem to be deaf to safety organizations that plead for total prohibition. They all suffer from personal blindness due to the same attribution failure and use senseless arguments like "we canít check it, so we donít restrict it". By prohibiting the handheld and allowing the hands-free, they contribute to an incorrect assumption that the first one is dangerous and the second one safe. Besides that, it is very simple to prohibit car kits.

A switch of roles?

When we think about safety in the chemical industry, we all assume the government will adhere to safety legislation. We trust the government because it has no commercial interest that can obscure a clear view on safety policy. The topic of hands-free phoning shows that parts of the chemical industry are more concerned with our safety than is the government. As I hope that everybody can reach their destination safely, this topic letter is a call to governments to face the facts and prohibit car kits. It is never too late to let the scales fall from your eyes. This will help to convincing others that phoning and safe driving donít go together.


Juni Daalmans

April 2013


More information on brain based safety can be found on and in the book "Human Behavior in Hazardous Situations. Best Practice Safety Management in the Chemical and Process Industries." 2012 Elsevier

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