Table 1.

A summary of travel policies and definitions of essential travel by different institutions across the world.

Institutions	Time	Definition of Essential Travel
U.S. Centers for Disease Control and Prevention	August 2021	The CDC does not impose uniform restrictions on domestic travel, allowing states to adopt different travel restrictions. Regarding international travel, the CDC identified a notice–Warning Level 3: Avoid all non-essential travel to certain destinations.
California Department of Public Health	April 2021	Essential travel is travel associated with the operation, maintenance, or usage of critical infrastructure or otherwise required or expressly authorized by law, including work and study, critical infrastructure support, economic services and supply chains, health, immediate medical care, and safety and security.
Selected universities in the U.S.	May 2021	Essential travel in university is defined as those that are necessary and cannot be postponed or handled remotely. (i.e., for graduation, academic progress, core educational, business functions of the University, etc.)
New South Wales Government	July 2021	Although NSW does not provide a definition of essential travel, it does specify appropriate means of transport for certain people in its guidelines. In addition, the guide defines the people who are allowed to make essential travel, and provides recommended means of transport for different travel times. In particular, it mentions that public transit, taxis or carpooling are not allowed to travel.
European Commission	May 2021	The EU does not give the definition of essential travel, but gives the people whose travel belongs to it, including but not limited to: healthcare professionals; seasonal workers in agriculture; transport personnel; passengers in transit; passengers travelling for imperative family reasons; third-country nationals travelling for the purpose of study, etc.
Canadian Government	June 2021	Some of the travel purposes that are considered essential may be: economic services and supply chains; critical infrastructure support; health (immediate medical care), safety and security; supporting goods for indigenous communities; any other activities that are deemed non-optional or non-discretionary.
British Government	June 2020	Essential travel may include the following travel purposes: to obtain basic necessities, including food and medical supplies and supplies for the essential upkeep, maintenance and functioning of the household, or to obtain money; to seek medical assistance; to travel for work; to fulfil a legal obligation; to access critical public services, including educational facilities, social services, etc.