## 1 Introduction
With the rapid development of information technology and Internet of Things technology, there are some technical means for monitoring the conditions and use of a single parking space [23; 24; 25]. Mining, analyzing and applying the data of \"parking time, vacancy time, turnover number\" of parking spaces in different spatial locations can provide a new path to improve the overall parking spaces utilization efficiency and parking satisfaction degree. On the basis of the literature review, the supply demand characteristics of parking spaces were further excavated, as shown in (Table 1). By analyzing these indexes, the supply-demand characteristics of parking spaces in different spatial locations within the parking lot were revealed. In order to further elaborate and visualize the above demand characteristics indexes of parking spaces, the Metro City complex in Shanghai, China was taken as a case to illustrate. The Metro City complex is located in Xujiahui district, Shanghai. It is an urban complex of retail, catering, leisure entertainment and service supporting facilities. There are 10 floors in the complex. The first basement floor, first floor, second floor and third floor are for retail and catering. The fourth floor is for retail, catering, leisure, entertainment and supporting service facilities (photography, beauty salon). The fifth floor is for catering, leisure entertainment (cinema, theater) and service supporting (beauty salon). The sixth floor is for catering. The seventh floor is for leisure and entertainment (karaoke). The eighth floor is for catering and leisure entertainment (yoga). The second basement floor is a parking lot with 185 parking spaces. The parking lot is divided into two parking zones: A and B. The vehicle entrance is in the south of the complex, and the vehicle exit is in the middle part of the complex. There is an elevator L9 in zone B, which stops from the first floor to the fifth floor. There are four elevators in zone A: among them, L10, L11 and L12 reach all floors, while L14 cannot reach the basement first floor or the seventh and eighth floors. According to the plan structure diagram of the parking lot, the GIS model of the parking lot is constructed, as shown in Figure 1, which describes the locations of the entrance and exit, the elevators, and the drivers' driving flow line. In order to obtain the demand characteristic indexes of the parking spaces, it is necessary to investigate the utilization characteristics of the parking spaces in the parking lot. The vehicle plate number, entry time and departure time are identified by the parking lot access control data. The occupation conditions and information about the vehicles parked in the parking spaces are identified by the video patrol method. In addition, in order to analyze drivers' preferences for parking spaces, a parking space choice preference questionnaire was designed. Based on the literature [7; 8; 9; 10], the factors that affect drivers' choice of parking space mainly include \"the distance between parking space and entrance\", \"the distance between parking space and elevator\" and \"occupancy of parking spaces on both sides of parking space\". The respondents were required to score the three factors on a scale of 1 to 5 [26]. A total of 96 valid questionnaires were obtained, and the recovery rate was 91%. The respondents were drivers who entered the parking lot. The survey took place between 10:00 and 20:00 on 27 March 2020. According to the survey data, the parking demand characteristics indexes are obtained. 1. [label=(0)]
2. Parking space turnover number. During the survey period, the turnover number of parking spaces in the parking lot ranged from 0 to 8 times, as shown in Figure 1(a). The turnover number of parking spaces in zone B is generally high, with an average of 4.50 times. The turnover number of 20 parking spaces in the upper right corner of zone A is also high, with an average of 3.75 times. The average turnover number of parking spaces in zone A is low, with an average of 2.26 times.