# Influence of the Analytical Segment Length on the Tram Track Quality Assessment
## 3 Results  
The five-number descriptive statistics for the calculated values of W and J indices by lengths of the analytical segment are given in Table 5. The values of the W index on the analytical segments range between 0 and 1, where the value of the median, depending on the length of the analytical segment, is between 0.33 and 0.42. The values of the J index calculated on the same analytical segments range between 0.00 mm and 5.52 mm, where the value of the median, depending on the length of the analytical segment, is between 0.73 mm and 1.40 mm.  
The distributions of the calculated W and J indices according to the track sections and analytical segment lengths are presented in Figure 7. Each row presents the distribution of the synthesized index on L1, L2A, and L2B track sections calculated on consecutive segments, from top to bottom: 200-, 100-, 50-, and 25m long segments.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Percentile**} & \multicolumn{4}{c}{**W (-)**} & \multicolumn{4}{c}{**J (mm)**} \\ \cline{2-10}  & **200 m** & **100 m** & **50 m** & **25 m** & **200 m** & **100 m** & **50 m** & **25 m** \\ \hline Minimum & 0.02 & 0.01 & 0.00 & 0.00 & 0.37 & 0.25 & 0.20 & 0.00 \\ First & 0.14 & 0.12 & 0.12 & 0.08 & 0.72 & 0.61 & 0.54 & 0.46 \\ Quarter & 0.42 & 0.37 & 0.35 & 0.33 & 1.40 & 1.04 & 0.91 & 0.73 \\ Median & 0.46 & 0.45 & 0.44 & 0.44 & 1.66 & 1.45 & 1.24 & 1.02 \\ Third & 0.81 & 0.79 & 0.81 & 0.82 & 2.42 & 2.14 & 1.76 & 1.38 \\ Quarter & 1.00 & 1.00 & 1.00 & 1.00 & 4.87 & 4.96 & 5.52 & 4.83 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Five-number summary for the calculated values of W and J indices.  
Figure 7: Distribution of the synthesized tram-track quality index W and J.  
One can see in Figure 7 that there is a certain regularity in the distribution of both TQI calculated values, i.e., that the calculated TQI values for the analytical segments are proportional. Furthermore, reducing the analytical segment length in the case of the W index leads to a redistribution of the W index on shorter analytical segments while retaining the value level in relative terms. In the case of the J index, reducing the analytical segment length reduces the value of the J index on shorter analytical segments.  
The distribution of the W and J indices calculated for different analytical segment lengths is presented in Figure 8. Their values are displayed as stacked bar lines. The bar line closest to the center line presents track geometry quality calculated for the 200m long analytical segment. Calculated W index values are categorized using different colors, where the green color indicates good quality (W < 0.2), the yellow color indicates satisfactory quality (W < 0.6), and the red color indicates insufficient quality (W \(\geq\) 0.6) of the track geometry in operation. The distribution of the J index values is presented in a similar way, where the J index values are classified according to colors with a step of 2 mm.  
Table 6 presents the share of W and J index limit values calculated for different segment lengths regarding the length of the entire network. Reducing the analytical segment length increases slightly the share of tracks with a good track quality W < 0.2 while the share of tracks with unsatisfactory track quality W > 0.6 decreases. On the other hand, reducing the analytical segment length significantly increases the share of segments with J < 2 mm and reduces the share of tracks with J > 4 mm.  
Figure 8: Track quality W and J index distribution along the tracks.