## 2 Materials and Methods  
### Research Methodology  
For the development of this research, the Design Science Research Methodology (DSRM) was used to show the entire process of justification, development, and testing [4]. In addition, tools and activities were added to expand the research carried out. In general, the research methodology is organized in five stages: (1) identification of observed problems and motivations; (2) the objectives of a potential solution; (3) design and development; (4) demonstration; and (5) evaluation. The activities and research tools that describe the scenario for each stage are specified below. Figure 1 shows a diagram of the research methodology.  
The first stage identified the problems associated with current road inspection methodologies, maintenance, and analysis, which use time-consuming and resource-intensive equipment and strategies. The proposed method should reduce the time spent collecting the required data or obtaining the same data and reduces associated costs. To identify current tools to achieve the above requirements, a literature review was carried out, based on Web of Science search engines, using keywords: photogrammetry, road analysis, and Structure from Motion (SfM). The use of Scopus and related technical repositories allowed collecting articles emanating from congresses related to innovation in engineering and geomatics, in addition to referring to various research documents published in the last 15 years, to define activities, processes, problems, tools, capabilities, and equipment that will be essential in continuing the research. Once the necessary elements are recognized, a primary objective is defined, satisfying a potential solution. For this case study, the extraction of information from the exploitation of virtual models created using 3D reconstruction is defined by applying algorithms based on photogrammetry techniques and Structure from Motion (SfM), flight planning for UAVs, and capture of photographs to build the virtual scenario that will be able to provide relevant information in the analysis of roads and in obtaining a longitudinal profile associated with it.  
In the third stage, the proposed methodology was designed and developed based on the knowledge and tools obtained from the literature review. This consisted of defining techniques and planning flight aspects for UAVs, techniques for accurate photo capture, learning, and application of virtual reconstruction software based on SfM algorithms and specialized software application for model analysis. Subsequently, the activities that lead to obtaining the longitudinal profile associated with the path are defined to obtain indexes and characteristics related to the roughness and deterioration that the route possesses.  
The proposed method was implemented in the fourth stage; parameters and flight conditions for the UAV team were established; camera focus considerations and storage capacity and energy expenditure were estimated. The photographic records were uploaded to the Context Capture 3D modeling software, and the result was exported to a specialized analytics software called Power GEOPAK, which belongs to the same Bentley Inc. product line. The longitudinal profile of the path is obtained and used to calculate the IRI through existing techniques and proposed simulations.  
In the last stage, a comparative analysis is carried out between the IRI values obtained in the study with the values of the official IRI certificate provided by the state road authority, which dates from the time the road was put into operation. Finally, considerations and recommendations are established to apply the method to be used in future work.  
Figure 1: Research Methodology.