Evaluation of a fragrance system to counter sleepiness at the wheel

Important results from the project

Driver fatigue is an important cause of traffic accidents and the prevention of fatigue has been the focus of research in the automotive industry for many years. To achieve the zero vision in the number of injured and killed in traffic, further development of innovative solutions is required to prevent fatigue-related incidents. The purpose of this project was to test whether a fragrance system can increase the driver´s alertness level. Tests were performed in a controlled environment to determine if the fragrance system is an efficient countermeasure against driver fatigue.

Expected long term effects

The fragrance system that was tested had a measurable effect on the driver´s sleepiness, driving performance and attention, but the effect was not specific to the active fragrance substance that was tested, but a similar effect was also seen with inactive fragrance. This is in line with other driver fatigue countermeasures. Driving performance and fatigue can be improved for a short while. Whether this is sufficient to prevent fatigue-related crashes is a topic for future studies. The effect was not large enough to justify further development and integration of the product in vehicles.

Approach and implementation

The fragrance system was tested on 21 sleep deprived drivers who drove twice in a simulator. Active fragrance or inactive substance was administered during the drives in a crossover design. The effects on the driver´s sleepiness, driving performance and attention were evaluated. Self-rated sleepiness, objective signs of sleepiness (e.g., long blinks), and driving performance (e.g., line crossings) were measured before and after fragrance exposure. Changes in sleepiness and driving performance due to fragrance exposure were compared between active and inactive fragrance.