Factors Influencing the Carbon Footprint of Major Road Infrastructure—A Case Study of the Učka Tunnel

In addition to its positive socioeconomic impact, tourism also has some negative effects on the environment, particularly through carbon dioxide (CO 2 ) emissions. Although the impact of tourism on the environment is visible, many of the cause–effect relationships have not yet been adequately explored. In order to determine individual factors regarding the temporal variation in the carbon footprint of a major road infrastructure facility (the Učka Tunnel, Croatia), a regression analysis was conducted. The study analyzes the carbon footprint of the pre-pandemic and pandemic periods and uses factors at the national and regional levels influencing the region of Istria County, as representative of the developed tourism regions in the Mediterranean. The results of the research provide theoretical insight into the sustainability and cause–effect relationships between the economic and social factors of road transport in tourism-developed destinations, with characteristic seasonality. At the application level, the research results can be used to predict the temporal variations in the environmental impacts of road infrastructure, as well as economic parameters that can be used in the prediction process and crisis management models of major road facilities.