• Machine vision monitoring of five posture parameters reveals that the anti-wind tunnel with holes provides superior posture stability compared to other windbreaks.
• In tunnel sections, the tail car exhibits larger posture amplitudes than the head car, while the opposite is observed in non-tunnel sections.
• During tunnel transit, posture amplitudes peak at a specific speed, indicating a critical speed that most adversely affects operating posture.
• The findings provide crucial insights for enhancing operating safety and ride comfort of conventional passenger trains under crosswind conditions.