## 3 The Integral Role of Lighting in Urban Environment
### Assessing Subjective Indicators of Lighting Quality  
The next objective in _Phase 4_ of the present study was to confirm the validity of the sustainability coefficient (Sn) by analyzing subjective indicators of environmental comfort for all selected sites. For this step, the SEC method (suitable for everyone, environmentally accepted, cost-effective) [11] was used. This assessment included an examination of the subjective indicators under the'suitability for everyone' dimension. The complete model SEC is presented in the Supplementary Materials as Table S1. Each location was examined using the psychological, sociological, and aesthetic-functional factors with associated indicators and aspects using five-level questionnaire term options within two extremes. The complete table is presented in the Supplementary Materials as Table S2. The standardized assessment of the sociological factor was further refined. The frequency of nighttime visits to a particular place is of paramount importance because it reveals how we subconsciously perceive that place during nighttime hours. This perception \begin{table}
\begin{tabular}{l l c c c c c} \hline \hline  & & \multicolumn{2}{c}{**Illumination Likability (L)**} & \multicolumn{2}{c}{**Illuminance**} & \\  & **Case Study Location** & – & & & **Intensity (l)** & **Sn** \\  & & \(\mathbf{x_{\mathrm{L}}}\) & \(\mathbf{\sigma}\) & \(\mathbf{x_{\mathrm{1}}}\) & \(\mathbf{\sigma}\) & \\ \hline \multirow{4}{*}{Street} & L1 Gosposka Street & 3.12 & 0.727 & 3.30 & 0.677 & 0.97 \\  & L2 Postna Street & 3.16 & 0.073 & 2.87 & 0.780 & 1.12 \\  & L3 Kocljeva Street & 3.49 & 0.902 & 3.71 & 0.850 & 0.96 \\  & L4 Vojänsńska Street & 3.24 & 0.947 & 2.90 & 0.824 & 1.14 \\ \hline \multirow{4}{*}{Square} & L5 Stukelj Square & 4.09 & 0.911 & 4.10 & 0.822 & 1.00 \\  & L6 Castle Square & 3.34 & 0.803 & 3.28 & 0.727 & 1.04 \\  & L7 Liberty Square & 3.25 & 0.831 & 3.40 & 0.830 & 0.98 \\  & L8 Main Square & 3.05 & 0.863 & 2.86 & 0.847 & 1.09 \\ \hline \multirow{2}{*}{Park} & L9 Slomšk Square & 3.34 & 0.803 & 3.28 & 0.727 & 1.04 \\  & L10 City Park Maribor & 3.14 & 0.955 & 2.53 & 0.851 & 1.26 \\ \hline \hline \end{tabular} \(\overline{x}\), arithmetic mean; \(\mathbf{\sigma}\), standard deviation; Sn, normalized sustainability coefficient.  
\end{table} 
Table 3: Descriptive measurements of the illumination intensity and likability of the locations and the results of the sustainability coefficient. is expressed in our willingness to visit the place after dark. This is essentially related to our mental acceptance of a particular place and its illumination at night. We added to this aspect by examining the activities we are willing to undertake in each place. Activities such as walking, sitting, socializing, and playing were included in the study. This part of the survey was also conducted with the same group of 200 people that we used in the introduction and first part of the survey. The results are shown below. The data collected by a questionnaire were statistically processed and analyzed. The results in the Tables 4-10 represent the arithmetic mean and standard deviation \(\sigma\) evaluation according to the SEC model for 3 factors (psychological, sociological and aesthetic-functional), 7 indicators (individual feeling, attracting attention, orientation ability, sense of safety, land use, site aesthetic, and artificial light effect) and 13 aspects (attraction, pleasantness, relaxation, composition, arouse interest, stimulation, overview, safety, usage intensity, space arrangement, fascination, comfort, and compliance). The remaining two dimensions of the SEC model for the selected ten locations were not specifically studied in this context.