## 4 Results and Discussions
### Crash Analysis of Oromia Region
#### 4.3.5. Crash Hot Spot Analysis  
The threshold distance for identifying crash hot spots was determined using the results of _Moran's I_ spatial autocorrelation analysis, which is shown in Figure 8. The threshold distance used in Getis Ord \(Gi^{\star}\) crash hot spot analysis is the distance at which crashes are highly clustered. As a result, the incremental spatial autocorrelation analysis of the Oromia region yielded a threshold distance of 161.764 kilometers with a statistical significance level of 0.10 (such that the \(p\)-value obtained is 5.14% \(<\) 10% thus, the confidence level is 90%). Even though the current analysis's first peak has been cut by more than half due to the reduced analysis coverage from regions to zones within a single region (Oromia), the threshold distance remains higher. As explained earlier (in Section 4.2), larger zones (e.g., Borena with 45,463 km\({}^{2}\) area coverage and Bale with 44,912 km\({}^{2}\) area coverage) necessitate longer distances to reach at least one neighbor from their centroids, resulting in a higher default _Beginning Distance_ and threshold distance. Figure 9 and Table 3 show the results of Getis Ord \(Gi^{\star}\) statistics for identifying crash hot spots in the Oromia region. Getis Ord \(Gi^{\star}\) statistics' crash hot spot analysis identified six hot spot areas, which are listed in the attribute table's result (see Table 3). The rankings were based on each zona's computed Z-score.  
Figure 6: (**a**) Crashes occurred in a day of the week: from 2014–2017; (**b**) Crashes occurred in the time of the day: from 2014–2017.  
Figure 7: Crashes analyzed by collision types: 2014–2017.  
Figure 8: The spatial autocorrelation of Oromia in (**a**) Graph and (**b**) Attribute table.  
Figure 9: Crash hot spot map of Getis Ord \(Gi^{*}\) statistics of Oromia region.  
According to the findings, the East 'Shewa' (E. Shewa) zone and 'Burayu' town (Burayu T.) have the highest values of crash severity clusters and are ranked as priority crash hot spot areas across the Oromia region with a confidence interval of 99%. According to Section 3.1 of this document, Addis Ababa is encircled by five major roadways. These are locally named as; (1) 'Ambo-Ber', (2) 'Tarma-ber' (3), 'Jimma-Ber', (4) 'Gojam-Ber' and, (5) 'Kality-Ber' or 'Bishoftu-Ber'. The AADT for freight vehicles entering and leaving Addis Ababa is estimated to be 10,725 and 12,890, respectively [73]. More than 70% of these entering and exiting freight vehicle shares have gone through Gate-5 (Kality/Bishoftu-Ber) [73], which is located in the East Shewa zone, Oromia's first-ranked crash hot spot. 'Bishoftu-Ber' is also the key entry point for import and export freight vehicles between Addis Ababa and the port of Djibouti. As a result, the East 'Shewa' zone was expected to experience higher traffic volumes and freight vehicles, which are directly related to the increased crash frequencies. When compared to others, issues related to the second crash hot spot zone, 'Burayu town,' were primarily associated with poor roadway facilities (such as narrow lane width, deteriorated pavement, lack of pedestrian walkway and so on).