# Cost Overrun Causative Factors in Road Infrastructure Projects: A Frequency and Importance Analysis
## 4 Cost Overrun Factors by Region: Limitations and Challenges  
Considering that 83.3% of the documents analyzed in the frequency and importance analysis are studies of projects in the regions of Asia and Africa, it is necessary to extend the analysis in regions such as Europe, America, and Oceania. In these regions, there were no major documents that complied with the inclusion and exclusion criteria; however, there are studies that analyze the factors of cost overruns in construction projects, from a qualitative perspective. These studies will be analyzed below in a discussion of cost overrun factors by region. To analyze the cost overrun factors by region, the authors have identified the factors reported in the documents by region, according to the top-15 cost overrun factors with the highest Influence Index presented in Table 7. Table 11 shows the relationships between these 15 factors and the regions in which they were reported. According to the document selection process for the America region, a single study met the three inclusion/exclusion criteria ([PERSON] [68]); this fact could be the reason why several top-15 factors that are not reported in the America region (Table 11); however, the information could be complemented with results from other studies. For instance, [PERSON] et al. [70] presents a study that uses information from road infrastructure projects in Indiana, United States, which highlights the relationship of the factor 'inadequate bidding method' with the occurrence of cost overruns in road projects. On the other hand, [PERSON] and [PERSON] [71] conducts a study of the factors that affect the cost of maintenance activities for road infrastructure projects in the United States, in which the influence of several of the top-15 factors is reported (Table 11): 'failures in design', 'inadequate project planning', and 'poor site management and supervision'. By the other side, [PERSON] et al. [80] present a study of the causes of claims related to cost overruns in construction projects in Canada, in which some factors coincide with those reported in Table 11: 'project scope changes', 'unrealistic contract duration', and 'inadequate project planning'. Other studies focused on cost overruns on construction projects in the North American region are [PERSON] and [PERSON] [81], [PERSON] and [PERSON] [82], [PERSON] and [PERSON] [83], related to the South America region: [PERSON] and [PERSON] [84], [PERSON] et al. [85], and [PERSON] et al. [86]; however, these studies were classified in the background category for not meeting any of criteria 2 or 3. Despite the existing studies, it is evident that in the regions of both North America and South America, studies of cost overruns factors in road infrastructure projects are lacking, which allow a better characterization of the cost overrun phenomenon. However, from the existing information, it is possible to infer that the top-15 of cost overruns in road projects in America is similar to that reported in Table 11, but further studies are recommended. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Influence Rank**} & \multirow{2}{*}{**Factors**} & \multicolumn{5}{c}{**Region**} \\ \cline{3-6}  & & **Asia** & **Africa** & **Oceania** & **Europe** & **America** \\ \hline
1 & Failures in design & & & & & & \\
2 & Price variation of materials & & & & & \\
3 & Inadequate project planning & & & & & \\
4 & Project scope changes & & & & & \\
5 & Design changes & & & & & \\
6 & Unrealistic contract duration & & & & & \\
7 & Inadequate bidding method & & & & & \\
8 & Legal issues & & & & & \\
9 & Late decision making by owner & & & & & \\
10 & Political situation & & & & & \\
11 & Financial difficulties of owner & & & & & \\
12 & Inadequate contractor’s experience & & & & & \\
13 & Poor site management and supervision & & & & & \\
14 & Economy issues & & & & & \\
15 & Poor site investigation & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Cost overrun factors reported by region.