## 3 Results and Discussion
### Model Development  
Firstly, the speed reduction in the vertical TCMs was observed. Table 2 compares the values in the different places. Although raised intersections provide safe crossings due to the speed reductions, it seems that, after the vertical deflection of the beginning, a higher value was recorded in the middle point of the TCM. However, they still provided a safer atmosphere for urban intersections. According to the results, it seems that raised crosswalks can be crossed at the highest speeds. The reduction effect of vertical deflections is said to be dependent mainly on its geometric design [45, 46, 47]. Their characteristics were  
Figure 8: Speed values in the measurement points in Eluterio Villaverde Street, in Basauri (Spain). Figure 9: Speed values in the measurement points in Gernika Street, in Basauri (Spain). not evaluated for this research, as it is outside its scope. The speed hump gave the lowest figures. Nevertheless, a unique place was evaluated so it is not regarded as representative. Finally, speed cushions caused an important speed reduction, although high maximum values can also be detected, 72 and 60 km/h. Nonetheless, the major interest of the manuscript is the relationship between the distance between different vertical traffic calming measures and the speed recorded in the intermediate points between them. A correlation was observed, and various functions were proposed to try to correlate the values. Table 3 exposes the analyzed models and the obtained determination coefficients (\(R^{2}\)). Almost all the models have a determination coefficient near 0.80, which implies a quite good correlation. Although they were not the best models for predicting the \(V_{85}\) and the \(V_{m}\), linear models were selected as the proposed ones due to their simplicity and their facility to be interpreted. Hence, proposed model for predicting the \(V_{85}\) in an intermediate point between consecutive TCMs is shown in Equation (1):  
\[V_{85}=34.36+0.075\cdot d \tag{1}\]  
where \(V_{85}\) is the 85 th percentile of the speed distribution in an intermediate point between consecutive vertical traffic calming measures and \(d\) is the distance between the axes of the TCMs. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Type of TCM** & **Street** & **Point** & \(V_{\text{max}}\) (**km/h**) & \(V_{\text{85}}\) (**km/h**) & \(V_{\text{m}}\) (**km/h**) \\ \hline \multirow{4}{*}{Raised intersection} & \multirow{2}{*}{Zachodnia} & RI 1 & 48 & 38 & 33.7 \\  & & RI 2 & 40 & 35 & 32 \\  & & RI 3 & 36 & 33 & 30.3 \\ \cline{2-6}  & \multicolumn{2}{c}{Mean values} & **41.3** & **35.3** & **32.0** \\ \hline \multirow{4}{*}{Raised crosswalk} & Zachodnia & RCW 4 & 39 & 37 & 33.8 \\ \cline{2-6}  & Pulaskiego & RWC 2 & 52 & 34 & 25.8 \\ \cline{2-6}  & \multirow{4}{*}{Eluterio} & RCW 1 & 56 & 36 & 28.9 \\  & & RCW 2 & 48 & 33 & 27.9 \\  & & Villaverde & RCW 3 & 53 & 38 & 29 \\  & & RCW 4 & 56 & 42 & 34.6 \\ \cline{2-6}  & \multicolumn{2}{c}{Mean values} & **50.7** & **36.7** & **30.0** \\ \hline Speed hump & Wschodnia & SH 2 & **39** & **21.2** & **16.8** \\ \hline \multirow{4}{*}{Speed cushions} & Zachodnia & SC 3 & 45 & 37 & 33.3 \\ \cline{2-6}  & \multirow{2}{*}{Transportowa} & SC 2 & 72 & 36 & 26.4 \\ \cline{1-1}  & & SC 3 & 60 & 31 & 21.7 \\ \cline{1-1} \cline{2-6}  & \multicolumn{2}{c}{Mean values} & **59.0** & **34.7** & **27.1** \\ \hline \multicolumn{2}{c}{**Mean values of all TCMs**} & **49.5** & **34.7** & **28.8** \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of obtained speed values at the traffic calming measures. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Analyzed Model Type** & \(R^{2}\) **for \(V_{\text{85}}\) vs. Distance** & \(R^{2}\) **for \(V_{\text{m}}\) vs. Distance** \\ \hline Linear & 0.817 & 0.795 \\ Logarithmic & 0.885 & 0.797 \\ Inverse & 0.828 & 0.706 \\ Quadratic & 0.875 & 0.799 \\ Cubic & 0.899 & 0.856 \\ Potential & 0.899 & 0.813 \\ Exponential & 0.788 & 0.779 \\ \hline \hline \end{tabular}
\end{table}