# Cost Overrun Causative Factors in Road Infrastructure Projects: A Frequency and Importance Analysis
## 1 Introduction  
In recent years the demand for road infrastructure projects has notably increased, this being due to road projects playing an important role in different aspects of a country's economy, health, education, competitiveness, and quality life [1, 2]. This is because designing, planning, building, and maintaining road projects are crucial activities for the well-being of a country. Undertaking a new road project involves a great economic effort [3, 4], which, in the case of failure, can seriously affect the national and regional economies [5]. Despite the importance, road projects have been associated with unwanted phenomena such as cost overruns, delays, disputes, corruption, and others, which have caused serious consequences, compromising the successful development of the projects [6, 7]. Due to the magnitude, road projects are related to different variables that together are difficult to predict [8, 9, 10]. Therefore, the estimation and development of costs in the project's lifecycle are associated with a high level of complexity and uncertainty [11]. At the end of a project, a deviation of the final cost with respect to the estimated initial cost may occur; this deviation can be positive or negative [12, 13]. A positive value indicates cost overrun, and a negative value cost underrun. Thus, the cost overrun is the phenomenon of greater affectation and financial risk for project owners,who are usually public entities that depend on public money that usually is associated with extensive controls, regulations, claims, and disputes [14]. In some projects, the phenomenon is caused by several reasons that are related to different project aspects, stakeholders, and even external variables [2]. In addition to this, each project in the construction industry is exposed to cost overruns for different reasons that may vary from one country to another and from one project to another [15; 16; 17]. In the worst cases, cost overruns can cause the construction activities interruption, and even the abandonment of projects, situations that occur when the owner does not have the financial capacity to meet the unexpected costs. Consequently, payments to the contractor must be suspended. The consequences of cost overrun in road projects have caused that researchers and professionals focus their work on the phenomenon, some on characterization and others in the search for solutions that allow mitigating the causative factors [11]. Despite efforts, the problem has remained, as evidenced in some studies [5]; [PERSON] et al. [17] analyzed 2668 road projects in the United States, finding 55% of projects with cost overruns. [PERSON] et al. [18] studied 231 road projects in Australia and determined an average cost deviation of 16.3%. [PERSON] et al. [19] examined 49 road projects in Australia, revealing a mean cost overrun of 13.5%. [PERSON] et al. [20] studied 37 Dutch road projects, where found cost overruns of 62.2% of the projects and a mean cost overrun of 18.6%. [PERSON] [21] studied 138 road projects in South Korea, finding 95% of the projects have a maximum cost overrun of 50%. [PERSON] and [PERSON] [22] considered 85 road projects in the Philippines, finding mean cost overruns of 5.4%. [PERSON] and [PERSON] [23] analyzed 169 road projects in Palestine; their results showed a cost average of 14.6%. [PERSON] and [PERSON] [24] studied seven road projects in Tanzania and finding average cost overruns of 44%. Evidence that allows concluding that the cost overrun phenomenon affects both road projects in developed and developing countries. To undertake the cost overruns mitigation in road projects, the initial actions should be focused on identifying the factors responsible for the phenomenon occurrence.