Why do Chinese drivers become angry? The role of olfactory interaction in road rage emotion modulation

• Jasmine and lemongrass oils reduce driving anger, unlike peppermint and patchouli which exacerbate it. • Chinese drivers' anger primarily triggered by other drivers' provocative road behaviors. • Peppermint oil shows unexpected negative effects on Chinese drivers, contrasting previous studies. • Cultural differences significantly influence essential oils' emotional regulation effects in driving contexts. Road rage is a negative emotional state that significantly impacts drivers’ emotions and safety. Olfactory interaction has shown considerable potential in resolving negative emotions and enhancing pleasure. This study aims to analyze the main factors influencing Chinese drivers’ driving anger and to assess the effectiveness of olfactory interaction in improving driving anger and increasing driving pleasure. The study consists of three parts. The first part is a survey involving 933 Chinese drivers, mainly aged between 26 and 50, to analyze the situational factors that induce driving anger and the acceptance of emotional regulation modalities. The second part involved the screening of olfactory interactive materials, and four typical materials were selected for experimental validation. The third part is an experiment on the modulation of anger emotions based on olfactory interaction. It involves 38 young Chinese drivers aged between 23 and 30, who were subjected to a simulated driving experiment to induce anger emotions. We used a 2 (with and without anger modulation) × 4 (jasmine essential oil + lemongrass essential oil + peppermint essential oil + patchouli essential oil) mixed-factorial experimental design, and four different olfactory intervention conditions for emotion conditioning were used in the simulated driving experiment. Self-assessment scales (SAM) were used to assess anger levels before and after the interaction, and Likert scales were used to assess the effects of anger regulation. Olfactory interaction was found to be an emotional intervention modality with high acceptance among participants. The scents of jasmine and lemongrass essential oils showed significant positive modulation of driving anger emotions, while peppermint and patchouli essential oils showed significant negative modulation. Olfactory interaction has shown clear effects in improving the driving anger and emotional modulation of young Chinese drivers. Intelligent products based on olfactory interaction have the potential to become an effective way to improve road rage and may be applied in smart cockpits in the future.