Table 1 Taxonomy of travel measures adopted during the COVID-19 pandemic

Travel advisory or warning

Health advice or warnings provided by government on country-level transmission of COVID-19 to guide individual decisions on travel. This may include information on how to avoid virus (e.g. wear masks)

Health screening

Evaluation of the health or exposure status of a traveller entering a country (we separate out testing and providing additional travel documents as travel measures). This includes temperature checks, travel history, and monitoring of symptoms at points of entry (self-assessed or otherwise)

Quarantine

Requirement that an international traveller be separate from other people in a designated location (e.g. home, hotel, government facility), for a designed period of time, if they have or may have been exposed to SARS-CoV-2 infection to prevent onward transmission and monitor for illness

Testing

Requirement that an international traveller undergoes, or provides evidence of, a valid COVID-19 test before, enroute, during, and/or after their arrival at their destination

Border closure

Complete closure of points of entry by land, sea and/or air without specifying targeted countries/population groups/travel routes

Restricting international air travel

Stopping the arrival of international flights, restricting the origin or number of flights, rescheduling of flights, or closing airports. The measure refers to specific countries or categories of travellers

Restricting international marine travel

Stopping, restricting or rescheduling marine travel (e.g. ferries, ships). The measure refers to specific countries or categories of travellers

Restricting international land travel

Stopping, restricting or rescheduling land travel (e.g. trains). The measure refers to specific countries or categories of travellers

Individual-based travel restriction/ban

Restricting/suspending the entry/exit of specific types of travellers based on particular characteristics (e.g., immigration status, occupation, health status)

Country-based travel restriction/ban

Generally restricting/suspending international travel between a jurisdiction and one or more foreign jurisdictions

Additional travel documents

Requiring international travellers to provide certain documentation or changing arrangements of the issuance/validity of travel documents, which include, but are not limited to, a health declaration form/questionnaire, entry approval letter, visa

Other travel measures

Any other measures regulating international travel which do not fall under the measure types listed above