Objective With the rapid development of urbanization and road motorization, problems such as air pollution, traffic safety and public health are becoming increasingly serious, which have caused inconvenience and even safety risks to children’s school trip, and profoundly affect children’s behaviors of school trip. A healthy and safe school trip space is a prerequisite for children’s active school trip and a humanized place to realize children’s free interaction and healthy growth. However, in China, there are currently problems such as narrow space, broken landscape and traffic accidents with respect to the school trip space for children, and existing evaluation tools have not fully formed a detailed theoretical framework while failing to effectively integrate with design work. Therefore, it is necessary to construct an environmental health and safety assessment system for school trip space.

Methods Based on the combing of literature regarding children’s cognitive and behavioral characteristics, the influencing factors of active school trip, and the behavioral characteristics of school-age children during their school trip, this research identifies the main needs of children during their school trip, namely walking safety and growth comfort needs, which include walking space safety, social environment safety, growth health comfort, and activity space diversity. Based on this, the research constructs an environmental health and safety assessment system for school trip space. In terms of data collection, the research collects data mainly through mining data on urban street and terrain, field shooting of streetscape pictures, field measurement and scoring, etc. Semantic segmentation of streetscape pictures, GIS visibility analysis, color entropy method, cosine law and other analysis methods are adopted.

Results In this research, 13 evaluation indicators are selected. These indicators include: Accessibility, safety of street crossing facilities, street crossing distance, school trip independence, crowd density, street eye surveillance coverage, monitor monitoring coverage, sound environment quality, green visibility, color richness, color harmony, accessible green biomass, and number of landscape facilities. According to the results of the hierarchical analysis method, walking safety has the highest weighting value of 0.35 and spatial diversity has the lowest weighting value of 0.13, which indicates that in the environmental health and safety assessment system for school trip space, the walking space safety is considered to be the primary factor influencing children’s active school trip, and the diversity of activity space has less influence.Through the stratified sampling method, the school trip spaces of Qiuyi Primary School, Qiantang Experimental Primary School and Shengli Primary School are screened out from the first batch of pilot elementary schools included in the “Comfortable Passage” program, with the health and safety assessment of the school trip space of such schools being conducted according to the environmental health and safety assessment system for school trip space. The results show that the average health and safety score of school trip space of the three schools above as a whole is 2.97 points, the average health and safety score of the school trip space of Qiushi Primary School is 3.27, higher than Qiantang Experimental Primary School (3.10) and Shengli Primary School (2.41). Through the interview survey, the access structure of the above three primary schools and parents’ attitude towards their children’s walking to school are obtained. The results show that the support degree of parents of students in Qiushi Primary School for their children’s walking to school is 63%, higher than Qiantang Experimental Primary School (50%) and Shengli Primary School (43%). In terms of the proportion of children walking to school, Qiushi Primary school (51.8%) is higher than Qiantang Experimental Primary School (47.3%) and Shengli Primary School (40%). The results of interview survey are consistent with the results of evaluation, indicating that the evaluation system has high accuracy.

Conclusion According to the evaluation results, the main problems in the school trip space of the three schools include the safety of walking, the insufficiency of space for rest and communication, the obstruction of social surveillance line of sight, and the lack of vegetation. Therefore, based on the current status and characteristics of regional construction, four targeted improvement strategies are proposed, including perfecting the infrastructure construction of school trip space, creating diverse activity spaces within school trip space, improving the landscape quality of school trip space, and establishing a social surveillance system for school trip space. The research results can provide guidance for the improvement of environment of school trip space and have important theoretical and practical significance for the construction of child-friendly cities. In addition, different from subjective evaluation and field survey, digital and parametric data analysis methods such as multi-source data, semantic segmentation and GIS visibility analysis are introduced into the environmental health and safety assessment system for school trip space to achieve objective and quantitative evaluation and analysis of the health and safety of school trip space, thus providing a scientific, standard and objective technical means for the evaluation of urban school trip space. Quantitative methods and optimization measures may also be applied to relevant urban research.