The travel cost method is a revealed preference technique used in ecological economics to estimate the economic value of non-market environmental goods, particularly recreational resources such as national parks, wildlife sanctuaries, lakes, beaches, and forests. Since these environmental amenities are not traded in conventional markets and do not have explicit prices, the travel cost method infers their value from the expenses people incur to visit them. The fundamental idea is that the time and money spent by individuals to travel to a site represent a form of implicit price, which reflects their willingness to pay for access to and enjoyment of the environmental resource. The conceptual foundation of the travel cost method lies in consumer demand theory. Individuals derive utility from visiting a recreational site, and the number of visits they make depends on factors such as travel expenses, income, availability of substitute sites, and personal preferences. By observing how visitation rates vary with changes in travel costs, it is possible to estimate a demand curve for the site. The area under this demand curve, above the actual travel cost, represents the consumer surplus, which is interpreted as the economic value of the recreational benefits provided by the environmental resource. In practical terms, the method begins by identifying a specific site whose recreational value is to be estimated. Visitors to the site are then surveyed to collect data on their place of origin, number of visits made during a given period, travel distance, travel time, mode of transportation, travel expenses, income level, and socio-economic characteristics. Travel cost typically includes direct monetary costs such as fuel, fares, tolls, and entrance fees, as well as the opportunity cost of travel time, which is often valued as a fraction of the visitor’s wage rate. These costs vary across individuals depending on how far they live from the site and how frequently they visit. Once the data are collected, visitors are usually grouped into zones based on distance from the site, such as concentric zones around the recreational area. For each zone, the average travel cost and visitation rate per capita are calculated. Alternatively, an individual travel cost approach can be used, where each visitor’s behavior is analyzed separately without aggregation into zones. Using econometric techniques, a demand function is estimated