## 3 Results
### Road Traffic Noise Modelling  
The 3D map based on the \"OpenStreetMap contributors\" source was used as the basis for the model. This included the basic geometric structures of the intersections, surrounding buildings, greenery, and other types of infrastructure. The map background was transformed into the appropriate coordination system \"Krovak S-JTSK (Ferro South/West positive) coordinate\". Individual intersections were divided into homogeneous sections from the point of view of the traffic flow characteristics (traffic volume, speed, and density), road gradient, etc. (Figure 8, Table S1). Individual road sections were assigned the following parameters: traffic volume, road type (local road), traffic flow speed, road surface, traffic flow type, road gradient, and wind rose. These parameters affect the resulting noise levels around the road (according to the principles stated in Section 2.5). The parameters of the surrounding buildings and other parts of the infrastructure around the intersection were also defined: height, reflectivity parameter, or noise absorption  
Figure 8: Distribution of homogeneous intersection sections (**a**) three-arm intersection-T_16, (**b**) roundabout-R_17, R_22 in the city of \(\dot{\text{Z}}\)lina. Figure 7: Comparison in 1–3 octave bands for equivalent noise levels from road traffic before and after the reconstruction of an intersection in \(\dot{\text{Z}}\)lina at MS1 for years 2016 (before reconstruction), 2017 (immediately after reconstruction), and 2022 (five years after reconstruction). of the surrounding areas. Calculations were conducted for the selected area of interest and also for the selected points (measuring stations and modeling points). Two measuring stations (MS1 and MS2) were chosen as reference points for the assessment, and real noise load measurements were also carried out. At the same time, one reference modeling point (MP1) was chosen near the exposed building for the comparison of the noise load coming from road traffic at the proposed intersections (Figure 3). Noise level limits for the daytime, evening, and night-time (Table 1) were defined for the selected points. Points marked in red represent areas exceeding the limit value for the noise level (Figures 9-11). Modeling of the noise load in the vicinity of the three-arm and roundabout intersection revealed differences in noise propagation from road traffic in the outdoor environment. Differences in the generation of noise from road traffic according to the design of the intersection were found. These may have an impact on the surrounding development of family or apartment buildings. The equivalent noise level was calculated using the model for three reference parts of the day: daytime \(L_{Aeq,day}\), evening \(L_{Aeq,evening}\), and night-time \(L_{Aeq,night}\). At all assessed points and for all assessed parts of the day (Table 8) limit values for the outdoor environment were exceeded (Table 1). Figure 10: Model of the spreading of noise emissions from road traffic in the vicinity of the new roundabout in the city of \(\hat{\text{Zilina}}\) (R_17) during the (**a**) daytime, (**b**) evening and (**c**) night-time. Figure 9: Model of the spreading of noise emissions from road traffic in the vicinity of the original three-arm intersection in the city of \(\hat{\text{Zilina}}\) (T_16) during the (**a**) daytime, (**b**) evening and (**c**) night-time. The models showed a reduction in the noise load at the roundabout compared to the three-arm intersection at the assessed locations MP1, MS1, and MS2 (Figures 9-11). The noise level reduction for the daytime (\(L_{Avg,day}\)) for MS1 (R_17) compared with MS1 (T_16) was 3.3 dB; for MS2 (R_17) compared with MS2 (T_16), it was 1.5 dB; and for MP1 (R_17) compared with MP1 (T_16), it was 2.9 dB (Table 8, Figures 9 and 10). After five years of roundabout use, we observed a slight increase in the noise level at the assessed locations. For all stations, this increase was 1 dB. This may have been due to wear and smoothing of the road surface [50].