# How Does the Built Environment Affect Mechanical Parking Space Planning: A Case Study in Xi'an City
###### Abstract  
Mechanical parking lots and spaces are known as the \"energy saver\" of urban space because of their small footprint, high efficiency, and environmental protection. However, the location and number of mechanical parking lots and space planning have become an important part of effectively exerting the function of mechanical parking lots. In order to explore the planning problem of mechanical parking lots, this study used the gradient boosting decision tree-Shapley additive explanations (GBDT-SHAPs) to measure the non-linear impact of the urban built environment on the mechanical parking spaces ratio and extract the optimal threshold of key variables. The results show that land use mix and distance to Bell Tower (CBD) are two key variables affecting mechanical parking space planning, and both have a non-linear relationship with the built environment. The threshold values are 0.83 and 7 km. The results will provide urban and transport planners with strategies for planning mechanical parking lots and spaces. m 2024 2  
efficiency, environmental protection, and energy saving. It can reduce the occupation of land, effectively solve the problem of parking space shortage and low parking efficiency, and thus reduce urban traffic congestion and environmental pollution. Therefore, mechanical parking spaces have important advantages and development potential in urban parking management. The proper planning and design of mechanical parking lots and spaces is the key to effectively relieving traffic congestion and reducing environmental impact. Therefore, it is necessary to carry out a reasonable planning layout of mechanical parking spaces and to determine the location and number of mechanical parking spaces by discussing the influence of factors on the construction of mechanical parking spaces, so as to provide theory and application for parking planning and urban planning. In order to reveal which factors have a greater impact on the planning and construction of mechanical parking lots and mechanical parking spaces, and to explore what built environments are needed to be equipped with mechanical parking lots and how many mechanical parking spaces are needed, so as to provide a theoretical and practical basis for the planning and construction of mechanical parking lots and parking spaces. Traditional linear regression and non-linear regression have constraints on the trends of the model, which may bias the predictive accuracy of the model and the degree of influence of the independent variable on the dependent variable, and thus bias the planning guidance. Therefore, the gradient boosting decision tree (GBDT) method was used to study the non-linear relationship between the mechanical parking ratio and the built environment. It has been shown that there is a non-linear relationship between the built environment and parking demand [1], and that there is a relationship between parking demand and parking supply [6]; therefore, there should be some relationship between the built environment and parking supply. The effect of built environment factors on the mechanical parking space ratio is quantitatively analyzed from global and local perspectives. The main contributions of this study are as follows: on the one hand, there are few studies on mechanical parking planning. Some studies have analyzed the internal organization, control strategy, site selection and cost, mechanical structure [7; 8; 9; 10; 11; 12], and the design of the device and intelligent system optimization of the single facilities, while there is a lack of regional planning studies that provide theoretical and practical support for the spatial layout planning of mechanical parking. On the other hand, very few studies have addressed the relationship between car parks and the built environment, especially mechanical parking lots, and there is a lack of analysis of the impact of factors. There are six sections as follows. Section 2 discusses relevant research in the field of parking lots and built environments.