An experimental study on pedestrian walking speed considering combined effect of heeling and trim

This study investigates the impact of inclined conditions on pedestrian walking speeds, focusing on both individual and crowd walking modes. A total of fifteen different combinations of heeling and trim angles were simulated to conduct a comprehensive evacuation experiment. The heeling angles $\alpha$ considered were $0^{\circ }$, $5^{\circ }$, and ${10}^{\circ }$, while the trim angles $\beta$ were $0^{\circ }$, $\pm {10}^{\circ }$, and $\pm {15}^{\circ }$. Results indicate that average pedestrian walking speeds in both individual and crowd walking modes follow a similar trend as the trim angle $\beta$ varies from $-{15}^{\circ }$ to ${15}^{\circ }$, with the heeling angle $\alpha$ at $0^{\circ }$, $5^{\circ }$, or ${10}^{\circ }$. Under combined trim and heeling conditions, the average pedestrian speed in crowd walking mode is more sensitive to changes in heeling inclination compared to individual walking mode. Furthermore, under the same inclination angles, pedestrian walking speeds in crowd walking mode exhibit a more concentrated distribution compared to those in individual walking mode. Moreover, analysis of the spatiotemporal distribution of instantaneous velocities reveals that the trends in walking speeds during crowd walking mode in inclined scenarios follow a similar pattern to those observed in individual walking mode. The results will provide fundamental guidance to the practical human evacuation from passenger ships.