Studies have focused on the negative effects of anger on driving performance, but insufficient research has addressed intervention methods to reduce these emotional effects. This research investigated how music mitigates the deterioration of driving performance associated with angry emotions in a simulated car-following task. Forty-three licensed drivers participated in this study, and they were randomly separated into two groups: an intervention group and a control group. First, all the participants completed a car-following task involving neutral arousal. Then, both groups completed the car-following task after the anger arousal task. The intervention group drove while listening to relaxing music, but the control group did not. Driving performance and electrocardiographic data were recorded. The results showed that participants who listened to relaxing music had significantly shorter braking reaction times and greater heart rate variability (HRV) than did those who did not listen to music. Relaxing music can reduce driving anger and improve driving behavior.