## 4 Analysis and Results
### Trends in RTCs  
The dataset used for the analysis comprised 4093 traffic crashes that occurred from 2015 to 2018. There were 9031 victims in the traffic crashes. A total of 19% of the RTCs included fatalities, while the remaining had serious injuries. The primary reasons for traffic crashes included sudden turning, speeding, and not giving way, which accounted for approximately 47%, 18%, and 15% of traffic crashes, respectively. The chronological trend of traffic crashes shows a decrease in fatal and serious injury traffic crashes within the available dataset, as shown in Figure 3. The authors of [56], which was also related to Saudi Arabia, attributed the decrease in severe traffic crashes to the installation of traffic cameras in their study. A seasonal and month-wise analysis of fatal and severe injury traffic crashes is shown in Figures 4 and 5, respectively, which also confirm the trend that the number of RTCs shows a general decreasing trend, between 1436 and 1438, on the Hijri calendar. A one-way ANOVA was performed to check the following null hypothesis: Lunar months do not have a significant effect on the occurrence of RTCs. The results of the ANOVA are shown in Table 2. It is shown in the table that the [PERSON]'s statistic (F-value) for the ANOVA has a probability (\(p\)-value) of 0.5, indicating a very low value of the statistic. The F-value is considered to be statistically significant if it has a probability of 0.05 or less, as per the standard criterion for statistical tests [57]. Hence, in this case, the abovementioned null hypothesis can be accepted. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Sum of Squares**} & **Degrees of Freedom** & **Mean Sum of Squares** & **F-Value** & **\(p\)-Value** \\ \hline
**Intercept** & 444,889 & \(1\) & 444,889 & 407 & 0.00 \\ \hline
**Month** & 11,496 & \(11\) & 1045 & 0.95 & 0.51 \\ \hline
**Error** & 26,239 & 24 & 1093 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: ANOVA tests for lunar months. Figure 4: Seasonal variation of RTCs in the study area [51]. Figure 3: Chronological trend of fatal and serious injury traffic crashes. The crash type \"fatal and severe injury RTCs involving a moving vehicle\" was higher than any other type of crash in the available dataset and was approximately 38%. Other prominent types of traffic crashes included those involving multiple vehicles (21% of RTCs) and running off the road (14% RTCs). The authors of [50] also reported the first two as common types of traffic crashes reported in the Eastern Province. The study area from which data were collected for this research is a part of this province of Saudi Arabia. Table 3 provides some descriptive statistics related to the number of victims of major injuries and deaths in RTCs within the available dataset. The severity index is very high, showing that almost all RTCs have at least one death victim, on average. The population of the Al-Ahsa area is reported to be 1.3 million [58]. The figures shown in Table 3 are high as compared with other studies found in the literature. The authors of [59] showed an annual rate of merely 3.3 for fatal traffic crashes in Iowa, USA, as compared with 352 in Al-Ahsa for the available dataset. In another study, ref. [60] reported 14.93 deaths per 100,000 people in Columbia, while it was 311 for the study area. Interestingly, when the annual rates for the occurrence of crash rates were compared with previous studies, they were not found to be higher for the study area. In a study completed by the authors of [59], the annual fatal crash rate was approximately 350, which is close to the value for the study area. The authors of [61] did not mention the fatal and major injury RTC rates per year, but this point was further validated by the following studies. On the one hand, [PERSON] et al. [62] reported a rate of 1463 per year for fatal and major injury RTCs for Addis Ababa, while [61] reported it to be 3631 per year for Torino (Italy).