Inattentiveness is a major risk factor in traffic crashes. Often, inattentive-ness is caused by distraction from the primary task, i.e. driving the vehi-cle. In this report a distraction is defined as an action, event, or physical or emotional condition from the driver, other people or objects that disturbs the driver and distracts his attention from the driving task. Examples are weather conditions, traffic volumes, outdoor commercials, music listening, eating or drinking, talking to passengers, use of cell phones, cruise control or navigation systems, stress, irritation and fatigue.

This report focuses on music listening while driving a passenger car. More than 90 % of all car drivers listen to music in the car. A literature study has been carried out to explore the relationship between music and car driving. Previous studies have shown that there is no clear evidence of how and under which circumstances music affects the driver behavior. Furthermore, only few studies have been carried out as field studies. This indicates that more research is needed.
This report investigates the effect of music on the driver behavior in a field study with nine experienced drivers. The hypothesis is that there exists music that can improve the driving behavior of car drivers compared to their usual choice of music. To test this hypothesis, two music programs were created: music A consists of instrumental music with a moderate tempo. It was designed to provide the car drivers a better driving experience. Music B consists of well-known, lyrical pop hits with a moderate tempo. Data is collected partly as Floating Car Data, partly as trip diaries to be filled after each trip.

The results show that music does influence the driving behavior. An anal-ysis of the 5th and 95th percentiles for deceleration and acceleration, re-spectively, shows that music B improves the driving behavior significantly (paired t-test, p < 0.05) on highways. This indicates that the drivers are more aware of the traffic. Music A seems to impair the driving behavior. However, since each driver is unique and experiences the effect from the music differently from other drivers, it is unknown whether music A can improve the driving behavior in other traffic conditions or using drivers with other characteristics.

This report concludes that different types of music result in positive or negative effects on the driving behavior compared to the usual choice of music. However, the result is based on only nine drivers. Additionally, the conducted field study revealed several shortcomings of the study design:
• The drivers are unable to link the risk of a certain driving behavior to the experienced disturbance from the music. Hence, further studies should concentrate on objectively measurable parameters such as acceleration.
• It is unclear how the term an appropriate driving behavior could be described in terms of speed, acceleration, road type, traffic volumes, etc. This definition is important for the evaluation of the effect of the music.
• Several variables have influenced the effect of music but their ef-fects are unknown. Further studies must consider whether or not these variables should be taken into consideration by applying more advanced collection methods.
• The drivers are unwilling to use the evaluated music in its present form. This is due to the lack of variation, an absence of the news bulletin and the fact that the drivers have to choose the music themselves instead of listening to a radio station.
• The use of a field study must be revised. Some drivers in the study felt less attentive in traffic or operate the radio to a larger extent. Further studies must deal with these safety issues before considering doing another field study of music.