## 3 Analysis of the Lighting Levels for an Urban Context
### In Situ Measurements of the Lighting Parameters
The following symbols are used; ID: road identification number; \(r\): road length; \(l_{c}\): carriageway width; \(l_{ss}\): sidewalk on the same side of the luminaires width; \(l_{so}\): sidewalk on the opposite side of the luminaires width; \(i\): luminaires arrangement type; \(p_{1}\) and \(p_{2}\): luminaires position with respect the centre of the carriageway; \(\mathrm{L_{ID}}\): luminaires identification letter (see Table 6); \(d\): luminnaires distance; \(h\): luminnaires height; \(t\): tilt angle of the luminnaires; \(n\): luminnaires number. For each analysed road, the average horizontal value and the minimum horizontal value of the illuminance have been calculated on the sidewalks (\(E_{h,atv}\), l\(\lambda\)); while the average luminance value \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**LID**} & **P** & **\(\Phi\)** & **\(\eta\)** & **S** & **\(T_{c}\)** & **Photometry** & **Image** \\  & **[W]** & **[Im]** & **[Im/W]** & **S** & **[K]** & **Photometry** & **Image** \\ \hline A & 166 & 13,194 & 79 & HPS & 2000 & - & - \\ B & 158 & 10,897 & 69 & MH & 3000 & - & - \\ C & 118 & 6099 & 52 & LED & 4200 & - & - \\ D & 114 & 7546 & 66 & HPS & 2000 & - & - \\ E & 169 & 11,412 & 68 & MH & 3000 & - & - \\ F & 114 & 6700 & 59 & MH & 4200 & - & - \\ G & 157 & 9988 & 64 & MH & 3000 & - & - \\ H & 118 & 6099 & 52 & MH & 4200 & - & - \\ I & 116 & 2430 & 21 & HPS & 2100 & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Photometric data of the luminaires at the present status. The following symbols are used; LD\({}^{\ast}\): luminaires identification letter; _P_: luminaire power; \(\Phi\): luminaire luminous flux; \(\eta\): luminaire efficacy; S: source type; \(T_{c}\): correlated colour temperature; HPS: High Pressure Sodium; MH: Metal Halide; LED: light-emitting diode. (\(L_{av}\), cd/m\({}^{2}\)) for the carriageways has been calculated. The measurements results are shown in Table 7 for the 12 analysed roads. It must be noted that, among the 12 analysed roads, six roads (roads 1, 2, 3, 5, 7 and 8) are not in compliance with the minimum lighting requirements shown in Table 4. In addition, if the energy consumptions are considered the following considerations can be made. The 77% of roads have a luminaire type with an energy class not adequate, i.e., the energy class is less than the minimum value according to the energy classification introduced by the local regulation of Emilia-Romagna Region (see Appendix A). Ninety-two percent of lighting systems of the carriageways have an energy class that is not adequate (see Appendix A). On average, the lighting systems of the 12 analysed roads consume \(6.0\times 10^{-2}\) W/m\({}^{2}\), while the installed luminaires produce, on average, \(6.3\times 10^{-3}\) l/m\({}^{2}\) on road surfaces. The road that consumes the most is the ID 4 with \(14.5\times 10^{-2}\) W/m\({}^{2}\); while the most energy efficient is the ID 3 with \(1.2\times 10^{-2}\) W/m\({}^{2}\). The road with the best production of average illuminance values per square meter is the ID 4 with \(28.3\times 10^{-3}\) l/m\({}^{2}\), while the least performing road is the ID 3 with \(1.6\times 10^{-3}\) l/m\({}^{2}\).