# Safety Risk Assessment in Urban Public Space Using Structural Equation Modelling
## 1 Introduction  
The city is representative of social living standards and human development civilization. It is already the central carrier of a region's politics, economy and culture [1]. To improve the city's population carrying capacity and economic efficiency, developers and the government are vigorously building urban public spaces such as rail transit and commercial streets. However, with the increasing area of urban public space, the complexity of space structure and the high mobility of personnel flow have increased the frequency of fire, stampedes and other safety accidents in subway stations, integrated commercial complexes, etc. In the past 20 years, the risks of urban public spaces have shown multiple, sudden and serious characteristics worldwide. For example, in 1993, a fire broke out in the underground building of an underwater palace entertainment complex in Hongqiao, Shanghai, China, resulting in 11 deaths and 13 injuries [2]. In 2003, an arson accident occurred at the Daegu subway station in South Korea, resulting in 198 deaths, 146 injuries and 298 disappearances [3]. In 2004, Moscow terrorists killed 40 people and injured nearly 100 people in a crowded subway station [4]. How to improve the safety of urban public space has become an essential bottleneck of urban development. Currently, most countries have taken improving urban safety as a new goal of urban development based on maintaining the existing functionality of cities [5]. Therefore, assessing the safety risks of urban public space on such a social consensus is of theoretical and practical significance. The risk of urban public space is mainly concentrated in public transport and commercial facilities, leading to waterlogging, fire, stampedes, earthquakes, epidemics and other emergencies. This is primarily because the urban public space is an open complex giant system. It includes the complexity of system structure, dynamics, uncertainty, group rationality and irrationality. All kinds of emergencies are interrelated and transformed, and compound, secondary, and derivative disasters occur simultaneously, which leads to an increase in the impact of urban public space safety emergencies [6]. Domestic and foreign scholars have conducted a detailed study on the mechanism of urban public space accidents, accident simulation, emergency evacuation management, risk assessment methods, etc. [PERSON] et al. conducted field experiments on students on German campuses to analyze their ability to perceive danger under the systematic changes in lighting, prospects, and escape opportunities [7]. [PERSON] et al. used a natural experiment to identify the crime risk by analyzing the maintenance time difference of nearly 300,000 street lamp blackouts in Chicago. They found that power failure would lead to crimes spreading to nearby roads, with robbery and motor vehicle theft having the greatest impact [8]. [PERSON] et al. developed a qualitative analysis tool, the DS3 model, and found that design measures for traffic infrastructure, open public space and buildings are the main channels for urban flood resistance [9]. [PERSON] et al. believe that improving traffic, for example by optimizing road and street infrastructure, can force people to slow down and improve the quality of the urban environment, ultimately reducing accident risk [10]. Safety risk assessment is the research focus in this field. Urban public safety risk assessment refers to predicting the future safety status of urban public space based on risk assessment and identification and assessing the severity of losses caused by risk accidents. The Ministry of Emergency Management of the People's Republic of China has promulgated Measures for Evaluation and Management of National Safety Development Demonstration Cities in 2020. Canada put forward risk analysis requirements for disasters and accidents [11]. Risk assessment is carried out every two years in the UK and every year in major cities to list the main risks and corresponding risk levels in the next five years [12].