Motorcycle Noise Annoyance in Residential Areas Along Popular Leisure Routes

Motorcycle noise along leisure routes constitutes a distinct environmental health burden poorly captured by standard road traffic noise indicators. This study derives source-specific exposure-response functions and examines non-acoustic predictors of residential motorcycle noise annoyance. A mixed-methods socio-acoustic design was applied in five study areas in Baden-Wuerttemberg, Germany. A community survey (N = 493) assessed long-term annoyance (12-month recall); a smartphone-based experience-sampling study (MotoApp; N = 213; ten days in summer 2022) collected hourly ratings. Acoustic measurements provided vehicle-specific L_Aeq,1h, L_AFmax,1h, and N₆₀; exposure-response functions were estimated using logistic regression and generalised estimating equations. In the long-term survey, 46.5% were highly annoyed by motorcycle noise, compared with 18.4% for passenger cars. Motorcycle exposure-response curves were markedly shifted; the 25-highly-annoyed threshold was reached approximately 16 dB lower in L_Aeq,1h than for passenger cars on weekends. Negative attitudes towards motorcycle riders, low coping capacity, and noise sensitivity were significant independent predictors. Source-specific assessment is necessary for motorcycle leisure routes. The 25-highly-annoyed criterion maps to approximately 52 dB L_Aeq,1h and 78 dB L_AFmax,1h on weekends, and to 25 N₆₀ events per hour-substantially below current road traffic guideline values-providing actionable thresholds for noise action planning.