In this work, a theoretical basis for a comprehensive assessment of the environmental hazard of wastes, which are formed during the functioning of critical infrastructure in residential territories, is de-veloped. In addition, a resource-saving (resource-recovering) system is proposed for ensuring the protection of natural environment and vitally important human interests from the anthropogenic impact of wastes, thus creating favourable conditions for the vital activity of a population. The study was con-ducted using mathematical methods, such as mathematical logic and vector algebra, for assessing the system of an ecologically safe critical infrastructure of populated areas. It is argued that the formation of a resource-saving system, which does not include wastes as its constituent element, provides the integrity of a closed material-raw cycle. Moreover, such a system reduces the formation of waste mate-rial masses (sources of environmental hazard) as a quantitative result of the system to zero. It is shown that environmental hazards in residential areas can be prevented in those places, where a system of processing construction and other products at the last life cycle stage as secondary resources is im-plemented and no hazardous wastes are forwarded for disposal in the natural environment. The ob-tained results can be used when assessing the environmental safety of concepts, strategies, pro-grammes and projects at federal, regional and sectoral levels in the field of resource saving, waste and secondary resources management, as well as for ensuring the environmental safety of residential are-as.

Digital infrastructure as an element of the «Digital Railway» of JSC «Russian Railways» involves the provision of objective, complete and up-to-date information about infrastructure facilities in digital form to solve a wide range of tasks - from engineering surveys carried out as part of the construction, repair and reconstruction of railway infrastructure facilities to the operation of autonomous (unmanned) rolling stock. One of the methods of obtaining such information is digital photogrammetry. At the same time, the highest measurement accuracy is required when determining the geometry of the railway track. When determining the geometry of the railway track with high accuracy through digital images, it becomes necessary to take into account not only the parameters of aerial photography and the quality of digital images, but also the features of image processing programs. The article presents the results of experimental studies of the accuracy of determining the geometry of the railway track using digital images as a result of processing them on the digital photogrammetric systems (DFS) PHOTOMOD and Agisoft Metashape (PhotoScan). The technical characteristics (CFS) of PHOTOMOD and Agisoft Metashape (PhotoScan) are given, the goals, objectives and content of the experimental studies performed are considered, the features of the experimental object, the characteristics of the aerial survey equipment and the methods of control determinations are described.