نشریه عمران و پروژه
سال پنجم شماره 11 (پیاپی 57، بهمن 1402)

The decision-making process is critical to the success of any construction project, construction personnel make decisions related to their duties every day and justify these decisions. Wrong decisions can disrupt the project in terms of time, quality, cost and relationships and can even impose exorbitant costs. On the other hand, design, engineering and construction include complex decisions with high uncertainty, so special attention should be paid to this part. The main goal of this research is to determine the dominant model of the decision-making process of experts in construction projects. In the first step, decision-making models will be identified through library studies, and then their decision-making processes will be determined by attending construction workshops and interviewing experts in the field of construction. In the next step, by communicating between the decision-making processes of experts and decision-making models, the most used model is determined through coding؛ In this research, based on the conducted research, the 3 dominant models used in the decision-making process of expert project managers are: the contingency model, the multi-criteria decision-making model, and the classic model.

The transportation system stands as a pivotal factor in a nation's development. It is imperative to underscore that transportation activities form the bedrock of infrastructure, fostering economic growth within a country. Rail transportation, as an age-old method for conveying passengers and goods, remains widely embraced. Its popularity is rooted in various factors, encompassing the abatement of air pollution, contributions to sustainable development, cost-effectiveness, and heightened security measures, among others. This research endeavors to scrutinize the environmental influences contributing to the upsurge in passenger numbers within the rail transportation system. The study encompasses a thorough investigation of diverse factors influencing the increment in passenger numbers. Key variables integral to this research comprise the quantity of passenger cars in active service and storage, the consumption of various types of oil, the aggregate count of passenger cars, and the average journey distance. Upon analyzing the findings, it is evident that the variable denoting the number of passenger cars in service and reserve exerts a noteworthy impact on the escalation of passenger numbers over recent years. Consequently, a strategic focus on these variables during long-term planning and policymaking holds the potential to augment passenger figures in the rail transportation system.

With the start of the corona virus from the city of Wuhan in China and its spread among other nations, a gray era began in the world. This crisis permeated all businesses and industries, including the airline industry. After the announcement of the World Health Organization (WHO) on March 21, 2020 regarding the epidemic of this virus, physical distancing was recognized as the best way to deal with the spread of this disease. Hereupon, the demand for transportation decreased to a significant amount and the airline companies all over the world entered an economic recession. An analysis published by the International Air Transport Association (IATA) states that the crisis has reduced revenue generated from passengers for the world's airlines by 55% (equivalent to $314 billion) in the year of the outbreak. Similar surveys in other countries have also shown a decrease in travel demand and by examining various companies, researchers have recognized methods such as using technologies to reduce the need for physical contact in airports, the policy of removing the middle seat, etc., to be effective. They have also encouraged the governments to support the airline industries. In this article, the performance of Iranian airlines in domestic flights in the years 2016 to 2021 is examined and using the extracted results, a comparison between the years including covid-19 and other years is made. Due to the homogenization of the passenger, cargo and mail variables for comparison, indicators have been defined by dividing each variable by the number of flights. The result of this comparison shows a decrease of more than 20% in the passenger index from 2019 to 2020 and an increasing trend in cargo and mail indexes in these years, which can be due to people's eagerness for online shopping in this era compared to in-person shopping.

The Road Administration is one of the most important organizations in Iran, which is responsible for monitoring the safety and health of roads. One of the main issues that this organization faces is road accidents, which are one of the main causes of casualties and physical and financial damage in communities. In order to reduce accidents, the Road Administration has annual responsibilities. These functions, according to global standards, include increased monitoring of drivers, improved traffic systems, driving safety training and improved road infrastructure. This study first defined performance indicators and traffic safety and then analyzed its results. The analysis of the results of this study shows that despite the positive performance of the road organization and the decrease in the number of passengers, an upward trend is still observed in the number of accidents and fatalities in traffic accidents on suburban roads.