The travel cost method (TCM) is a widely used approach in ecological economics for valuing ecosystem services, particularly recreational or non-market environmental goods. It is grounded in the premise that the time and money individuals spend traveling to a natural site reveal the value they place on accessing and enjoying that site. Unlike conventional market goods, which have observable prices, many environmental resources—such as national parks, forests, lakes, and beaches—do not have a direct market price. Hence, TCM provides an indirect mechanism to infer their economic value by analyzing the expenditures associated with visits, treating these costs as a proxy for the price of accessing the resource. At the core of the travel cost method is the assumption that people make rational choices to maximize their utility, which includes the enjoyment or satisfaction derived from recreational activities. The total travel cost incurred by an individual is often composed of multiple components: direct expenses such as fuel, public transportation fares, accommodation, entrance fees, and parking charges; and indirect costs, such as the opportunity cost of the time spent traveling and engaging in recreational activities. By collecting data on the number of visits, travel distances, and associated expenditures, analysts can estimate a demand function for the recreational site, representing the relationship between visitation rates and travel costs. This demand function can then be used to calculate consumer surplus, which reflects the total economic value derived from using the site beyond what is actually paid. The TCM can be implemented in either a single-site or multi-site framework. In the single-site approach, researchers focus on one specific recreational location and estimate visitation patterns based on travel costs from various origin points. Visitors are typically categorized according to their distance from the site, and regression techniques are applied to relate travel costs to the frequency of visits. This allows for the estimation of the recreational value of that site for different population segments. In contrast, the multi-site approach considers multiple alternative sites, acknowledging that visitors may choose among several locations offering similar recreational experiences. This approach helps correct for substitution effects, where the presence of a nearby alternative may reduce visitation at the primary site. Both methods require careful survey design and data collection to ensure accurate representation of visitor behavior. A critical step in the travel cost method is identifying and measuring travel expenses accurately. Direct