Source
In Illinois, residents are still allowed to leave their homes for essential needs like:
- For health and safety: seeking emergency services, obtaining medical supplies or medication or visiting a health care professional
- For necessary supplies and services: obtaining groceries and food, household consumer products, supplies they need to work from home, and products necessary to maintain the safety, sanitation and essential operation of residences
- For outdoor activity: walking, hiking, running or biking – including going to public parks and open outdoor recreation areas, except for playgrounds
- For certain types of work: Providing essential products and services at Essential Businesses or Operations or otherwise carrying out activities specifically permitted in the order, including Minimum Basic Operations
- To take care of others: Caring for or transporting a family member, friend or pet in another household
What about travel?
In Illinois, only essential travel is permitted and must be done in accordance with social distancing requirements. That includes travel related to:
- Performing Essential Activities, Essential Governmental Functions, Essential Businesses and Operations or Minimum Basic Operations
- Caring for elderly, minors, dependents, persons with disabilities or other vulnerable persons
- Receiving materials for distance learning, for receiving meals, and any other related services from an educational institution
- Returning to a place of residence from outside the jurisdiction
- Following the direction of law enforcement or court order, including to transport children pursuant to a custody agreement
- Returning to a place of residence outside the State for non-residents
looks similiar to California's, so discretionary travel would appear to be a violation. (misdemeanor in Calif if it was actually enforced)
Airlines are allow to operate to support "essential travel"