# BIM Visual Programming Tools Applications in Infrastructure Projects: A State-of-the-Art Review
## 3 Results and Discussion
### Analysis of Results by Topic of the Papers  
This section presents and analyzes the results of this bibliographic review considering: (1) type of VP tool used, (2) type of infrastructure project, and (3) life cycle stage of the projects. Figures in this section represent the temporal distribution of the reviewed contributions. The X and Y axes of these figures represent the number of works and the year, respectively. The percentages presented in the analysis of the figures relate to the number of reviewed papers. Figure 6 presents the distribution of the reviewed papers considering the VP tools and BIM software used by these studies. These figure groups the reviewed publications as follows: (1) Publications that used Autodesk Revit-Dynamo software (red bars). (2) Studies that applied Rhinoceros-Grasshopper software (blue bars). (3) Works that used the API-Python platform (green bars). The data in Figure 6 show that the contributions of the VP tools to this review are: (1) Dynamo, 21 works (80.77%); (2) Grasshopper, 3 publications (11.54%); and Python with 1 study (7.69%). These statistics indicate that the Dynamo tool was the most used by the reviewed publications. Another trend associated with this VP tool is that the annual production in 2018 and 2019 was 2.33- and 3.67-fold more than the total number of works associated with this tool in the 2014-2018 period (three papers). Therefore, an increase in these annual production rates is expected in the future. However, the publications associated with Dynamo indicate that the BIM models used Autodesk Revit  
Figure 6: Distribution by type of VP tool and BIM software used in the reviewed works. as host software, which is not focused on civil engineering projects. This suggests that the interoperability among VP tools has undergone less development compared with that presented by BIM software such as AllPlan Bridge, Autodesk Infraworks, Tekla structures, and Bentley Systems. Further research into this gap would improve the decentralization of the VP tool market for civil engineering by increasing technology transfer among VP tool development companies. Figure 7 presents the distribution of the reviewed publications by type of infrastructure project. This figure classifies the publications into the following categories: (1) bridges (red bars), (2) tunnels (blue bars), (3) roads (green bars), and (4) other infrastructure (yellow bars). This last project category groups those studies that only contribute with publications that are not part of the leading groups of infrastructure reviewed (bridges, tunnels, and roads). The data in Figure 7 show the following statistics by infrastructure category: (1) Bridges; the leading discipline with nine publications (34.62%). These statistics may be explained because bridges are infrastructure with elements of very complex geometry [128; 129], such as abutments, piers, and girder sections, which are challenging to model. VP algorithms have optimized these difficulties by reducing the complexity of their modeling. The studies focused on the application of VP tools to bridges include that of [PERSON] et al. [115], who modeled the bridge pier design using Dynamo scripts to automate the geometry modeling. Then, the 3D model of the structure was modeled through an extrusion command. [PERSON] et al. [123] generated a BIM parametric model to design railway bridge platforms using Dynamo algorithms. This parametric model reduced the geometric uncertainty during the transversal layout of this bridge typology. [PERSON] et al. [114] designed an algorithm for parametrizing highway-type bridge pedestrian platforms considering both the geometry and possible construction scenarios. (2) Tunnels; These infrastructures made the third-highest contribution with six papers (23.08%), and included that of [PERSON] et al. [110], who designed a parametric model in Dynamo to study the central axis deviations in tunnels during their transversal construction. This model was applied during the design and construction of a Ningbo province subway (China).