External determinants cover political factors, the economic situation, the news and travel media, and the marketing activities of tourism organisations. Determinants mean that many vacations are the result of a compromise between the motivations of the tourists and their personal determinants.

External determinants of travel behavior are the environmental and contextual factors that influence how and why people travel, independent of their personal preferences. Key determinants include socio-economic conditions such as fuel prices, inflation, and currency exchange rates, which dictate affordability. Infrastructure and technology play a massive role; the availability of high-speed rail, the reliability of public transit, and the prevalence of ride-sharing apps determine "mode choice." Urban form and land-use patterns—how far people live from work or leisure—directly impact travel duration and frequency. Additionally, political and regulatory factors, such as visa requirements, carbon taxes, and government travel advisories, act as "gatekeepers" for international movement. In 2026, environmental shifts and climate change have also become significant external drivers, as extreme weather patterns frequently disrupt seasonal travel flows and influence destination popularity.