建成环境视角下共享单车与地铁的竞合关系非线性影响分析OA

[Background]As an important mode of public transportation in medium-to large-sized cit-ies,subways effectively address the primary commuting requirements of urban residents over medi-um to long distances.Meanwhile,bike-sharing,as an emerging short-distance travel mode,provides an essential solution for bridging the"last mile"gap.The interaction patterns between these two modes directly affect the travel choices of residents and the overall efficiency of urban transport sys-tems.[Objective]This study aims to explore how optimizing the built environment can promote a more harmonious and effective cooperative-competitive relationship between bike-sharing systems and subways,which can be categorized into three typical patterns:extension travel,competitive trav-el,and supplementary travel,thereby enhancing the overall efficiency and sustainability of the urban transportation system.[Method]Based on land-use characteristics,transportation facility attributes,and socioeconomic attributes,17 built environment indicators,including the number of parking lots,Shannon entropy of land use,average housing price,and population size,are used as independent variables,whereas shared-bike ridership under the three travel modes is adopted as the dependent variable.An XGBOOST model optimized through a random search for hyperparameter tuning was established,and SHAP interpretability analysis was employed for variable importance analysis.[Result]The model evaluation results indicate that the R² values for the test sets of the extension trip and competition trip models were 0.84 and 0.82,respectively,while the R² value for the supplementa-ry trip model was 0.76.[Conclusion]SHAP analysis further revealed the nonlinear impact of parking availability,proximity to the city center,and population density on the competitive and cooperative relationships between shared bikes and subway systems.The effect of parking availability first de-creases and then increases,with extension travel remaining relatively stable,whereas supplementary travel follows an S-shaped curve,with diminishing marginal effects after reaching a certain thresh-old.Regarding proximity to the city center,the impact on shared-bike usage initially increased and then decreased.Specifically,the demand for extension travel was higher within 20 km,whereas com-petitive travel decreased with increasing distance,and the demand for supplementary travel dimin-ished beyond 15 km.In terms of population density,there was an S-shaped growth in the demand for extension and supplementary travel,with a significant increase in shared bike demand in high-density areas.However,competitive travel was less influenced by the population density and depended more on the availability of subways and other public transportation options.[Application]The findings of-fer valuable insights for urban transportation planning.In areas with fewer parking facilities,increas-ing shared-bikes deployment can enhance short-distance transfer efficiency.Additionally,in areas within 20 km of the city center,strengthening the integration between shared bikes and subways can significantly improve the transfer experience.By optimizing the built environment,shared-bike us-age can be increased,reliance on private cars reduced,traffic carbon emissions minimized,and a more sustainable and green transportation system can be achieved.