Due to the significance of environmental consequences in road construction projects, some common issues, particularly in the Middle East and Iran (a country with a significant position in the transportation corridor of the region), were taken into consideration. Thus, it was necessary to know the exact impacts of constructing arterial roads on the most important environmental parameters influenced by the matter. This was done in the form of a researcher-made questionnaire. The questionnaire, responded to by experts in the field, asked questions about the intensity of the most influential parameters on environmental issues during various stages of the projects. The project, which asked questions about the intensity of eight classes of environmental parameters (including water pollution, soil pollution, local air pollution, the protected areas of plants and animals, damage to natural scenery and the introduction of garbage, damage to the ecosystem, damage to cultural heritages, and noise pollution) in five stages (before implementation, during implementation, maintenance and repair, land use change, and after implementation,) was distributed among 385 people. Then, their proposed coefficients were obtained in the range of 1 to 10. Due to the significance of determining an optimal coefficient for each parameter, the new clustering method was implemented based on the coefficients assigned to various parameters. The number of convenient clusters for one of the multiple phases was obtained by implementing the new algorithm using R. Then, coding and the provision of the genetic algorithm were performed in MATLAB, and the ultimate optimal coefficients were obtained. When quantified coefficients were obtained, the following results were observed:
According to the analysis, the following parameters were considered the most influential in the respective stages: water resource pollution (3.598) in the “before implementation” stage, noise pollution (5.891) in the “during the implementation” stage, damage to the ecosystem (5.251) in the “land use change” stage, soil pollution (5.813) in the maintenance and repair stage, and damage to natural landscapes (5.675) in the “road implementation stage”. The above coefficients can be helpful for researchers in road construction projects. On the other hand, the following parameters had the lowest impacts on environmental parameters: damage to the ecosystem (3.162) in the “before implementation stage”, water resource pollution (4.426) in the “land use change” stage, and damage to cultural heritage (4.418, 4.402, and 4.493, respectively) in the “during implementation”, “maintenance and repair”, and “road implementation” stages.
Due to the necessity to prioritize projects in terms of their environmental consequences the obtained data were standardized to use the weighted scoring method based on project management standards for the extraction of the ultimate formula (Formula 6). Then, by inserting the quantified values of the intensity of eight-fold environmental parameters (in the present case, in the form of equivalence scores in the Leithold Method) besides ultimate coefficients, the environmental index of each project was obtained. Thus, the best projects could be sorted from that perspective.
The above method provides a systematic approach to assess projects based on their environmental impacts and guarantees that resources are assigned effectively and efficiently. Moreover, it makes it possible to consider decision-making processes clearly and can be significantly helpful in prioritizing projects that are in line with stakeholders’ and organizations’ environmental goals and values. Generally speaking, the above method promotes sustainability and the responsible management of resources in organizations and enables the recognition of projects with maximum positive impacts on the environment. Finally, the method can be easily developed in terms of the required parameters and phases. In addition, it can include the results of varying methods implemented to assess environmental parameters, even making it possible to compare them with other items considered by researchers.